This CRL Custom Vertical Sliding Ticket Window can be installed above the counter top without altering its surface. It is constructed of heavy gauge extruded aluminum in satin anodized or bronze anodized finishes. The sliding lower panel is glazed with 1/4" (6 mm) clear glass, and has spring tensioned guides to hold it in the raised position. Two spring loaded knob latches will secure the window to closed position. Pile weatherstripping along the lower frame prevents drafts. Frame protrudes only 1" (25 mm) on clerk's side, and glass channel installs easily in 1/4" (6 mm) thick glass.