Hydraulic universal compatible coupling converter WN-4 is designed as a platform or transfer to make sure that several kinds of brands can work together. There are several famous brands in the world, but the couplings are all have their features and different from others, so that the tools can’t connect and work together. E.g. if there are two brands in a fire brigade, when the pump of one brand under the maintenance, it means that all the tools of the brand can’t work, but the appearance of the hydraulic universal compatible coupling converter solved the problems, there are four kinds of coupling, traditional female-male coupling, CEJN female-male coupling, Mono coupling and Core coupling, so the tools with this four kinds of couplings can connect and work together.