The Deringer Model 30 is a double check detector assembly (DCDA II). It is available in 2″-8″ sizes and has been in production since 2014. The 2″ Model 30 is a 2 1/2″ device with adapters and couplings to give it 2″ FNPT connections. The body is made of stainless steel. The Model 30 uses a Type II bypass with a single check.