Instantaneous fittings are brass or aluminum couplings designed for use in forest fire fighting.
Since ends are interchangeable (there are no male or female hose ends) and connections are made with a simple quarter-turn, multiple hoses can be laid out and joined quickly.
Aluminum hose fittings have the advantage of light weight, while brass hose fittings are stronger and more resistant to cracking during installation.
All of these couplings come complete with expansion rings, however there also is replacement rings so that couplings can be reused.