Sledgehammer’s Hinged SetScrew Stop Collars are combine in two pieces and hinged at two-end 180 degree apart. The gripping force is applied by one row of SetScrew. . It tightens the collar to the casing firmly. They can be latched on the casing pipe without having to be slipped on. It’s easy to install. These are most effective where low annular clearance is encountered. These Stop Collars undergo a special Iron Phosphate coating process to prevent from Rust then coated with special Polyester Powder they are available in all sizes ranging from 4 ½ “ to 20 ”.