The MainGuard #77 Post Hydrant provides the best in performance and value. Designed and engineered specifically for flushing, the #77 provides excellent flow rates for improving chlorine residual levels and flushing disinfection byproducts (DBPs) to keep water safe for consumers. The unique valve design allows for a full clear-channel flow that is superior to other blow-offs for moving water and passing debris easily. The #77 plunger is also designed to allow for throttling the flow of water while at the same time covering the drain hole to avoid unnecessary erosion. The MainGuard #77 comes standard with all brass principle working parts, 2″ FIP vertical inlet, 2 ½” NST outlet, traffic break-away, and locking security cover. The #77 is self draining and non-freezing, The MainGuard #77 is fully serviceable from above ground. Certified to NSF/ANSI 372.