400DD-90AL by Dixon Valve | Cam & Groove Spool Coupler | 90° Elbow | Type DD | 4" Coupler x 4" Coupler | AluminumConstruction: Seal: Nitrile Rubber Safety Notes: Under no circumstances should cam and groove couplings be used for compressed air or steam service! Pressure rating recommendations are based on the use of mating Dixon fittings at ambient temperature 70F (21C) with a standard seal installed. For use at elevated temperature or other unusual operating conditions, consult Dixon. How It Works: To make a connection, simply slide the adapter into the coupler