The mounting clamp can be positioned horizontally or vertically for mirror arms and rails of either orientation. Also, the clamp may be omitted to create an "L" bracket for mounting to flat vertical surfaces, such as the side of a motorhome or the back of a Jeep. All models include stainless steel mounting hardware. Use three-way mounting brackets for single or dual antenna installation on your car, truck, van, motorcycle or motorhome. If your mounting surface is strong, these mounts will easily support antennas up to 5' (1.5m) tall. The actual size of the bracket is 2.25" (57mm) wide by 2.9" (74mm) high. With the stud in place, the total height is 4.2" (107mm). They protrude outward from the vertical surface 1.9" (48mm). Using the standard bolts supplied with the bracket, you can install it on a tube with a diameter up to 0.850" (22mm). If longer bolts are used, the maximum tube diameter is 1.5" (38mm).