In open chock, there are many different types of open chock, roller chock, double roller chock, three roller chock, etc. We will discuss all roller chocks in another category. This open chock’s advantage is convenient use but disadvantage is less SWL. So it is mainly used on boat, barge, small dock, etc. Both open and closed chocks used on yachts are made of stainless steel material. On yachts, they are fixed by bolt and nuts, or layed in the FRP yacht hull. But when used on commercial ship or dock, they are often welded or casting therein. Welcome to contact us for more details. We can provide them in China, Korea, Taiwan, Japan and Hong Kong.