Quarter windows were of sliding rather than hinged construction. The receiver is hinged and more rigid with a Picatinny rail for mounting optics. The top of the camera had hinged doors for placing photographic plates. In a top-break revolver, the frame is hinged at the bottom front of the cylinder. The bladder has a small opening, sealed by a hinged door. These include an endless belt with jugs attached and a reciprocating device with hinged valves. The model would slide out of a double hinged opening door to one end. Lip can be hinged or telescopic type. These casement windows usually were hinged on the side, and opened inward. The canopy was hinged on the starboard base and opened sideways. A suicide door is hinged on its trailing edge. Pilot access is via individual hinged doors. The elevators are usually hinged to the tailplane or horizontal stabilizer. Most have fixed side walls and a hinged tailgate. The large canopies are sideways hinged.