Seems like JSAUX noticed dbrand’s Project Killswitch and decided to make their own alternative. While dbrand may have had to revise their Killswitch with the removal of magnets, JSAUX didn’t need to do that at all. No magnets here. Here’s some thoughts on the review sample I was given. Unboxing video available on YouTube.

The ModCase is an interesting concept. It allows you to control how far you want your Steam Deck to be customized and protected.

The basic kit is $30 and comes with the following:

  • protective case
  • cover
  • strap for attaching accessories
  • detachable kickstand
  • protective case for the official dock

If you pay a little more, you can choose what accessories to go along with the ModCase, be it a cooling fan, a USB-C hub, a M.2 slot kit, or a power bank. If you want you can get all four with the Ultimate kit, which will set you back $150. JSAUX sent me the cooling fan along with the kit, so I’ll have some comments on that later on.

The Case

You put the Deck inside the case, bottom side first into the corners, and then fold the top parts over the triggers. While this is relatively easy, be careful if you have a skin applied to the Deck; you don’t want it to get peeled off while you’re putting the case on. The back is semi-transparent, so if you have the clear shell on, you can still see the Deck’s internals, at least somewhat.

It’s difficult to describe the texture of the case. There’s no description of what the material is made of on the store page other than “PC-ABS and silicone.” The case is textured on the front corners where your palm rests and on the back grips. It’s comfortable though, I can tell you that. Of course, cutouts are provided by the headphone jack, the top and back vent grills, the USB-C port, the power LED, shoulder buttons/triggers, back buttons, MicroSD card slot, etc. There’s even a little cutout in the center of the back part of the case where you can still see Valve’s logo if you have the vanilla back shell. This cutout also serves as the “attachment point” for the strap and other accessories.

The volume rocker and power button have both been covered over. And enough of a cutout was made on the USB-C port that you can perfectly attach a 90-degree USB-C cable without there being a loose connection, unlike the Funalot case. Another advantage the JSAUX ModCase has over the Funalot case is the front corners of the Deck are covered. The advantage this has is it not only gives your palms a resting place, but I’d argue it would also provide slightly better protection should you drop the Deck face first.

One downside to this case is the cutouts on the back aren’t wide enough to accomodate the click-y back button set with the clear shell.

A nice feature with this case is it includes a kickstand. Not only is it detachable, but the stand is made of metal, ensuring that it won’t break as easily as it would plastic. Simply push the stand outward to let the Deck sit on your desk, then push it back in when you’re playing. Very fast, very easy. This is yet another advantage over the Funalot case, where the latter’s kickstand is made of plastic and you can’t get it out as quickly due to the mechanic it uses.

Preferably the kickstand would be right in the middle on the back to ensure equal weight on both sides while it’s resting, but obviously we can’t do that here since there’s the attachment point. Still, you can put some pressure on the Deck while it’s resting; it’s not going to go anywhere. Only complaint with the kickstand is you can’t really adjust the viewing angle all that much. It protudes outward by about 45 degrees and you can’t push it out any further.

Front Cover

The front cover – if it wasn’t obvious enough already – keeps your screen protected. Inside is a rectangular piece of foam that goes over the screen when it’s applied. There’s also a label for instructions on how to put the cover on or take it off. When putting it on, you align the top part first, then press down on the bottom. Then when you take it off, do the reverse: lift the bottom up first. If you do this with enough force the entire cover should be lifted off.

With both this and the back part of the case attached, you basically have a complete case for your Deck. Insertions are provided where the thumbsticks are so that the cover stays secure. Cutouts are still provided for the power button/LED, USB-C port, and volume rocker. The top vent grills are covered. So if you’re out in the rain, you’ll have most of your Deck protected. Just don’t turn it upside down since the back vent holes aren’t covered. Don’t tilt it upwards either since the cutouts can let liquid seep into the USB-C port.

Kind of curious why they left the volume rocker exposed. I guess if you were playing music or something you could adjust the volume while the screen is covered. But it makes sense to have the USB-C port exposed so that you can charge the device while simultaneously protecting it.

The cover isn’t super secure. There’s a little bit of leeway towards the top where the triggers are. Not enough where you could accidentally have the cover pried off, but just something to be aware of.

The Strap

Ah. The thing that I’ve been making a meme about since it looks so much like a watch. Just put a LED screen in there and you’ve got a working watch that you can take with you on the go. Or just attach your wrist along with your Deck and now you’ve got some serious power packed into your arm.

JSAUX ModCase using the strap as a watch

In any event, the strap doesn’t use magnets. No adhesives either, meaning no sticky residue left behind. No harm done to your Deck. You just slide the “watch” part of the strap into the attachment point on the back of the case, and from there you can strap on whatever accessory you want. The most common example I can think of is a power bank. Or maybe a USB-C dock.

While the strap does make the accessory secure, it’s a bit of a pain trying to apply it. Say you put in a power bank. You wrap the strap around it. Getting the “knot” from one side of the strap and pushing it through one of the holes on the other side is tedious. On top of this you have to deal with the fact that the “lips” of the strap can move around while you’re doing this. So if one side of the strap falls out, it’s because the lip that’s secured to the “watch” part got loose.

Removal of the strap is easy. Just slide it off the attachment point and you’re good to go.

Protective Cover for Dock

Honestly, to me it was a little odd for JSAUX to supply this along with the basic kit, but if you have the official dock from Valve, you’ll benefit with this. Initially I thought it was its own stand…until I realized the Deck just fell right through when I tried to put it on since there’s no “feet” to support the weight. Instead this is a cover that goes over the official dock.

JSAUX ModCase dock cover

As I don’t have the official dock I don’t have much else to comment about this. I guess it will be a nice touch for your dock though.

Cooling Fan

The cooling fan by JSAUX is compatible with and without the ModCase. With the ModCase on, you just need to take the clip off, then you can slide it into the attachment point. Unlike other cooling fans, this fan actually has a separate battery. So when you’re using it, you’re not sipping more battery from the Deck while it’s on. A knob is provided on the side where you can turn it on or off, and adjust the wind speed (up to 6,000 RPM).

JSAUX cooling fan

According to JSAUX, the battery is 2,000 mAh and lasts anywhere from four-to-six hours, depending on how fast the wind speed is set to. It takes an hour-and-a-half to fully charge via the USB-C port on the bottom. A 90-degree angled USB-C adapter is provided to make it a little easier to connect when the fan is attached to the Deck.

JSAUX cooling fan knob

Some people feel like there is a need to keep your Deck’s temperature down. I got a comment on a video I did going over if it’s worth using a fan for your Deck, saying “temps going up to 92-95C can´t be good for the APU over time.” So I guess there’s that.

A cooling fan, even with an external battery, doesn’t spell longer battery. In fact, in the brief testing I did, the battery life was even worse. Gotham Knights lasted five minutes longer without the cooling fan. My guess is that the lower CPU/GPU temperature with the fan on allowed the Deck to squeeze in more power to the CPU/GPU cores, therefore consuming more battery. So if you were looking to extend your Deck’s battery life, cooling the temperature is not the way to go.

I’ll need to do some more testing here. Ideally I’d like to run a game capped at 30 or 40 FPS, with a set TDP limit, then try testing again to see if my first test was actually using more battery with the CPU/GPU temperature cooled down.

JSAUX claims that the Deck’s temperature can cool down as much as 18 degrees C. Results have varied from individual to individual. One person told me that it’s pretty close; they saw a 16-17 degree drop. In my testing I’ve only seen a 14 degree difference. But yes, you’ll certainly be able to cool the APU’s temperature down, if you see any benefit of doing that.

I think a cooling fan would make more sense when your Deck is docked. I’ll let the commenter on my video do the talking for me:

Comment on cooling fan

Modular Case That’s Far Less Expensive than the Killswitch

I don’t have the Killswitch so that I can compare directly. What I will say, though, is the basic kit for the ModCase is half that of the Killswitch basic (or as they refer to as “essential”) kit. The front cover isn’t even included and that itself would tack on another $15. While the Killswitch may have a backplate mount for mounting additional accessories, dbrand hasn’t even made any add-ons for it yet.

Only benefit I see with the Killswitch is the choice of a Deck skin. Ergonomics and durability might play a different role as well. Again, I wouldn’t know since I don’t have one.

Is the ModCase worth the $30? I’d say so. It’s neat to have a modular design where you can add and remove components at will. You have a case, a kickstand, a watch strap to put on additional accessories, a front cover, and a cover for the official dock. JSAUX already has additional accessories with which you can further enhance your experience, with a USB-C hub, a cooling fan, a M.2 to USB-C converter, a power bank, what have you.

Only noticable issues that I have so far is the kickstand could kick out a little further, and the strap needs improvement as to how accessories get secured. I’m also disappointed that I can’t fit the click-y back button set through the case. I like that set of back buttons. The front cover being somewhat loose is also a little bit of a downside, though it’s not that significant.


The good:

  • pretty good price for what you’re getting
  • case, front cover, kickstand, strap, and dock case all included in basic kit
  • comfortable case while simultaneously protecting the Deck
  • modularity allows you to add and remove accessories easily
  • kickstand is made of metal
  • strap allows power banks, USB-C docks, and other accessories to be attached
  • cooling fan keeps your Deck’s temperature down

The not-so-good:

  • front cover is somewhat loose
  • kickstand only goes out by about 45 degrees
  • strap is a PITA to work with
  • click-y back button set with the transparent shell will NOT fit through the case

You can buy JSAUX’ ModCase over on their store.

Review sample sent courtesy of JSAUX. Opinions are of my own.