Tele Vue Gibraltar HD4Description Our longer, heavier 4" scopes are best matched to the rock solid Gibraltar HD4 mount. The large bearing surfaces and thick wood legs best handle the loads, especially for high power viewing. Leg extensions raise the altitude axis to 5 feet, still ideally sized for use with our Air Chair observing stool. Scale on leg extensions allows repeatable setting to desired height. A wood accessory tray ties the legs together for rigidity. Built in