Cylinder Protection Add to quote to select, and choose quantity on the quote form. Grid view List view 100 lb LP Acetylene Collar Add to Quote Coarse Thread Cylinder Cap – 3 1/8″ x 7 Thread HP Course Cylinder Cap 3 1/8″ x 7 Thread Add to Quote Cylinder Construction Collar 100LB Construction Collar Add to Quote Fine Thread Cylinder Cap – 3 1/8″ x 11 Thread HP Fine Cylinder Cap 3 1/8″ x 11 Thread Add to Quote Threaded Collar with Cap Add to Quote