C.R. LAURENCE B512B CRL 1" Nylon Sliding Screen Door Spring Tension Roller - Bulk 50/Pk. CRL Spring Tension Roller is used by several patio door manufacturers. The steel spring is coiled in a "S" configuration, and is made of heat treated, high tension steel spring; used by several patio door manufacturers. The nylon wheel has a 1/4" (6.4 mm) center groove. Two roller assemblies with installation screws per package..
