The Prime-Line M 6145 Frameless Glass Door Shower Top Bracket Roller Assembly is used to replace damaged or missing frameless shower door top roller assemblies. The shower door glass roller assembly has a diagonal mounting slot and is adjustable by sliding the roller up or down in the diagonal mounting slot and then tightening when you have it at the desired height. This sliding door rollers replacement has a top hung design. The assembly clamps onto the top of the shower door glass with a vinyl glazing gasket. This is a tub and shower door roller assembly used on frameless glass shower doors. The sliding shower door roller assembly accepts up to 3/16 inch thick glass panels. This sliding roller assembly has an oval edged 3/4 inch nylon ball bearing roller attached to an aluminum bracket. Please refer to the line art drawing for dimensions and compare with your needs before purchasing.