The Truth window egress hinge 30463 and 30818 – Replacement is the Wi1477, which is sometimes used for truth window hinge with Truth Operators. We find the number 30818 stamped on the window track, and the number 30463 stamped on the arm that goes from the window track to the arm attached to the window. We sell this window hinge in pairs, meaning top and bottom. If your window is the opposite hand, then the bottom hinge goes to the top, and the top hinge goes to the bottom. The egress hinge is used when the fire codes require a certain width opening for the windows. This hinge only slides over about 2-1/2″ into the opening for safe exit through the window. This hinge can be used as a replacement for the Wi1475, which are usually stamped 30744, 31133C, 40942 and 40941. For more information visit our website.