It is specifically made to fit the X40 hydrotherapy penis pump. It is very easy to fix and it is made from material that is safe and gentle to the skin. It is easy to clean and can easily be removed whenever you want. It makes the X4O hydrotherapy more comfortable and pleasurable to use. Using the X40 hydrotherapy, your penis will get wider and longer and the X40 replacement helps it sit better in the Bathmate pump.