REV 45mm U Channel has a 45mm x 45mm square profile, and is designed to work seamlessly with existing REV 15mm Extrusion. It can be used in locations where additional torsion strength is required. On the sides of the channel is the Extended Motion Pattern which uses M3 hardware for attaching brackets, extrusion, and channel together. Locations for mounting bearings, shafts, motors, and servos are available every 16mm. Slots on the top of the channel accept standard M3 hex-head bolts or nuts, rather than expensive t-nuts. The top of the channel also has the Motion Pattern with M3 holes on a 16mm diameter circle pattern repeating down the channel.