Plain back tandem roller assembly with two 1-1/8 inch concave steel ball bearing rollers

The stamped steel housing is adjustable

Used by MIlgard as well as other manufacturers primarily on vinyl patio doors

The housing is 3/4 inches wide and 1 inch tall with a 1/4-20 threaded mounting hole on the back end and an optional use 10-32 threaded hole on the top