SLIDING DOOR ASSEMBLY – This roller assembly is a four roller pocket door roller assembly used on Kennaframe pocket doors and a variety of other pocket door manufacturers ADJUSTABLE – The pocket door rollers are affixed to an adjustable spring-loaded steel bracket; they ride in a double track mounted in the top of the pocket door opening; the dial-adjust wheel makes it adjustable up to 3/8 inches in height STRONG AND DURABLE – Made of stamped steel housing with a nylon roller, these sliding door rollers are strong, durable, and built to last DIMENSIONS – The housing of the pocket door roller assembly can be used on doors 1 inch to 1-3/4 inch thick; the four diameter nylon rollers measure 23/32 inch NOTE - Please refer to the door roller assembly line art drawing for dimensions and compare to your needs before purchasing (Not Universal)