This is a 1-3/16 inch concave steel ball bearing roller assembly that installs into a 1/2 inch deep x 2-15/16 inch long mortised pocket on each end of the solid wood closet door bottom rail. The roller assembly is held in place by two 3/4 inch long screws. The bracket is stamped steel with a 1-3/16 inch steel grooved ball bearing roller. It rides on a metal track installed onto the floor. Used by a variety of manufacturers of sliding solid wood closet doors.
These rollers are constructed from steel and feature a center grooved design. They easily fit a 2-15/16 in. x 7/16 in. mortise slot in your door rail. Each roller has a load carrying capacity of 50 lbs. Used with your sliding wood panels.