Compact faucet lever for a faucet with a rounded triangular shape, 42mm from flat to opposite point of the triangle. On my faucets these snap-fit and we've been using a pair in the bath room for a month now.

I wanted to print them in boring silver, but the kids wanted color, so we color-coded hot and cold. Of course, you have to place the lever so it has enough clearance to turn far enough.