The Prime-Line N 6965 Mirror Door Roller Assembly is a bottom mount roller assembly used on metal framed mirrored wardrobe doors. Used by Bay King and a variety of other manufacturers, the T-shaped tab on the back end of the mirror closet door rollers slides up into a T-shaped channel in the door frame which holds it in place. The concave nylon ball bearing roller of the sliding door rollers replacement is 1-1/4 inches in diameter. For further roller assembly sliding door dimensional information, please see the line drawing.