JACK Polyurethane Rubber Posted on June 4, 2013 by admin JACK Polyurethane Rubber JACK Polyurethane Rubber mainly use as air lock and can be supplied either in sheet or strip form. The size available; Size: 6mm THK X 1m X 1m Size: 5mm THK X 1m X 1m Precut services to cut into strip form are available upon customer’s request