If you look around there are smaller 2/3/4/5 keys ones (which are obviously smaller), other examples: https://www.walmart.com/ip/2-Keys-Programmable-Mechanical

If you look around there are smaller 2/3/4/5 keys ones (which are obviously smaller), other examples: https://www.walmart.com/ip/2-Keys-Programmable-Mechanical-Keyboard-Macro-Keypad-Red-Shaft-Switch-Usb-Diy/838052186?wmlspartner=wlpa&selectedSellerId=101094691 https://www.walmart.com/ip/2-Keys-Programmable-Mechanical-Ke... https://www.walmart.com/ip/Hatatit-Mini-4-Keys-Macro-Mechanical-Keyboard-Gaming-Keypad-with-USB-Data-Cable-for-Windows-Mac-OSU-etc-HID-Standard-Keyboard/494687119 https://www.walmart.com/ip/Hatatit-Mini-4-Keys-Macro-Mechani... but I have never seen one like the silicon keyboard, if you are into DIY there are n projects/kits to make one, and of course in these cases you can choose tiny buttons instead of keys, but a minimal size is needed because the thingy should be programmable, though nothing prevents from getting the controller from any el-cheapo USB keyboard and connect to it the keys/buttons like the original ones on the larger "normal" keyboard. Try searching also for "osu keypad".