The Razor HD LER Wide Angle Eyepiece gives you a much wider view and is great for long range work. Using premium, high density, extra-low dispersion glass, the fixed-power Razor HD LER Wide Angle Eyepiece produces optimum resolution and color fidelity. 18x zoom when used with the Razor HD with 65mm objective 23x zoom when used with the Razor HD with 85mm objective Waterproof and fogproof 31mm eye relief The Razor HD LER Wide Angle Eyepiece is specifically designed for use with 65mm and 85mm Razor HD spotting scopes - not compatible with the 50mm Razor HD models. Mfg: Vortex Optics