The 8" Watts 772DCDA Double Check Detector Assembly was produced from 1993-1997. Very similar to the 770, with exception to the shutoffs. The 772 uses a special shutoff that are not standard. Two different sizes on the flanges make it unique. The body is a two cover, epoxy coated ductile iron construction. The check assemblies are stainless steel toggle linkage type. They use a vulcanized clapper plate. Check springs are contained when the cover is removed. Spring tension must be removed to repair the device. The device has replacable bronze seats, but a seat removal tool is required. The bypass device was a 3/4" Watts 007M1