This is two piece roller assembly used on Ador Hilite patio doors. The outer housing is 5/8 in. wide, 31/32 in. tall with a 11/32 in. flare width and has two hook tabs on top. The inner housing holds a 1-1/2 in. steel ball bearing roller. Together, they create an adjustable roller assembly that hooks into the bottom door rail and then is held in place by a 1/4-20 machine screw placed into the back end.