Have a cordless screwdriver? Feeling a bit lazy and want to build something cool out of aluminium extrusions but can be bothered fiddling about with a 'L' shaped allen key?
Well this 2.5mm hex key bit is the correct size to use with our M4 screws. They have a button head with a 2.5mm hex recess.
Use this with a cordless drill or screwdriver and you can put screws in or take them out at rapid prototyping pace, although be careful - set your drill torque ratchet to low to prevent any damage to the screws or thread if you accidentally cross thread them.