Storz couplings are a type of coupling also called 'sexless coupling'. Rather than having a male and female end connected by threads, it provides for identical ends to be joined together. Storz couplings are not screwed, but the connection is made according to the principle of a bayonet lock. The connection is made by joining the two pieces in such a way that the hooks of each go into the slots of the flange of the other. They are then rotated in opposite directions until they are tight together, creating a watertight connection between the internal seals. The main advantage of using Storz couplings is speed: generally, a coupling can be made with a 1/4 turn where with threaded couplings it is necessary to make several turns to make a tight connection.