The 2" Ames 3000B Double Check Detector Assembly is a bronze bodied, single cover device. Designed for fire line protection, it features a metered bypass assembly. It began production in 1998 but has recently been discontinued. It utilizes a inline check design with a single access cover. Plastic check modules are self contained and are held in place by a retainer directly under the cover. The check modules come apart for service with a quarter turn to the module. No special tools are required for servicing.