The SV-1 Switchview Throw Lever from Vortex is a riflescope accessory made for select Razor HD Gen II series zoom optics. This tool clamps to the magnification ring and allows the shooter to quickly zoom from minimum to maximum and precisely dial in the required magnification setting. The skeletonized aluminum throw lever adds minimal weight to the scope, and the corrosion-resistant anodized finish provides a layer of durability to the ridged construction. Compatible with select riflescope magnification rings with a diameter of 1.669 inches / 42 mm: Viper PST riflescopes with rubber magnification rings Viper HS riflescopes with rubber magnification rings Diamondback HP riflescopes