The 8" Watts Series 709DCDA Double Check Detector Assembly began production in 1979 and is still currently being produced. The early models were tagged as 709DDC which was later changed to 709DCDA. It features an epoxy coated cast iron body. Usually blue in color. Two cover design. The 709 uses self contained bronze check assemblies. The seats are bronze and replacable. In 2010, A lead free version was introduced, designated with a "LF" prefix. In 2013, the regular leaded devices were discontinued, Lead Free version is the only 709DCDA available. From 1979-1991, the bypass device was a 3/4" 709. 1991-1993 the bypass featured the 3/4" 007M1. From 1993-1998 the bypass device was the 3/4" 007M2. From 1998-present, the bypass device uses a 1/2" 007. Be sure to check the I.D. plate on the bypass for your specific device. No special tools are required for servicing