Using a hydraulic tool helps reduce the chance of installation damage. Rapid and safe installing tools for flexible rod seals. Includes 3 sizes to cover just about any rod seal installation job from 0.87" up. Stainless steel,which is of good and. It is very easy to use,only two steps are needed.And with the hydraulic cylinder sealing tool,you can quickly complete the installation of the seal and it doesn'for t take a of effort.