Sprockets, wheels, and gears, oh my! We really like our DC gear motors (a.k.a "TT Motor") but unless you have a 3D printer it can be a challenge to get something attached to the axle. That's why we've got this TT Motor Hub - it snaps onto the end and gives you two big flanges with holes. It's a very good solution to quickly and easily mount custom wheels, cardboard & wood, or other mechanisms to your robot project. We have tested these that they won't slip on the shaft! A wonderful, wee component you never knew you needed!