4Wheel Trolley Roller Bearing Assembly Fits 15/8 Inch High Strut Channel
Roller Trolley Has a Height of 7mm(0.2756in) in the Center Space, so You can Choose a set Screw of 7mm(0.2756in) or Less When Installing the Strut Channel, Which Will not Obstruct the Back and Forth Sliding of the Trolley.