SKYLOONG GK21S テンキー 2 モード DIY キット

Very easy to assemble, comes with a keycap puller, works great as a control pad for my home studio. Used Cherry MX Purple switches with it.

I got this to pair with my GK61XS. I know the GK21S is 6-row while the GK61XS is 5-row, so this would likely match a GK87 Lite better, but whatever. The lighting is nice and bright, the Skyloong customization software is decent to use, but leaves a lot to be desired in terms of the lighting settings.
The included pamphlet is a great reference guide, since there are some serious FN+ shortcuts for managing keymap, lighting, and even a battery indicator, as Jennifer's review mentions. The battery indicator is the ". Del" key and can be toggled using the FN key then tapping the .Del key.
I personally bought the keypad to use it primarily wired, with maybe Bluetooth usage when on-the-go or traveling.
Also worth noting is that the keypad actually comes with a small amount of foam already inside it to try to dampen the sound of typing and using it. I replaced it with some Poron and prefer that sound, but it *does* include some foam.
Easy addition for me to do for my typing setup, and the price at time of purchase ($43.99) is below retail for many other competing shopping platforms, and the shipping was rather quick for "free shipping." If you need a numpad or want a macro pad, this might be worth a shot if you prefer DIY over pre-built offerings.

I wish it wasn’t Bluetooth - it is sleeping half the time and then doesn’t register the first couple of buttons I push. Additionally the rgb automatically turns on when I plug it in to charge which is pretty annoying as my desk is in my bedroom and I am trying to sleep. Otherwise it’s a totally fine num pad!