These testers come assembled with Printed Circuit Boards (PCBs), so if you’re in the mood for modding, half the work is already done for you. If you opt for the Cherry set, you can try your hand at the following:

Cherry MX Red, Brown, Blue, Black, Clear, Green, Linear Grey, Tactile Grey, and Milk (White) mechanical switches.

If you opt for the Gateron + Rare Set, you get the following:

Five Gateron switches (Red, Black, Brown, Blue, Clear [35 g]) and four Cherry switches (Linear Grey, Tactile Grey, Milk [White], Green).