Element Optics Rf Rangefinder ModuleThis Element Optics RF rangefinder module functions best when paired with a rifle scope. Thats because it doesnt have a viewfinder, which means the module itself cannot be used to observe. Instead, it comes supplied with a mounting ring, which allows you to easily attach it to a Weaver Picatinny accessory rail. The Element Optics RF rangefinder module has a tube diameter of 30mm and you can use it with whichever mounting ring you want. But the