Product Description This tandem roller assembly is constructed from nylon. It features an adjustable top mount design with round edge nylon wheels. It fits Acme and like styled doors that are 3/4 to 1-3/4 in. thick. From the Manufacturer This tandem roller assembly is constructed from nylon. It features an adjustable top mount design with round edge nylon wheels. It fits Acme and like styled doors that are 3/4 to 1-3/4 in. thick.