The DI Optical 3XPRA is a magnifier that has been designed for use with the full range of optics including the EG1, FC1, RV1 and RV2. The 3x magnification significantly improves accuracy on medium to long range targets. It is housed in a waterproof aluminum alloy housing and has multi-layer coated scratch resistant lenses for extreme ruggedness. This optic conforms to the Mil-Std 810G Environment Testing. It comes with a Arms #78 mount. DI Optical 3XPRA Ring Mount Adaptor for ARMS #78