Want to be a better shot caller? Put a Viper Reticle Eyepiece on your Viper HD 85mm spotting scope and it becomes the perfect optical measuring stick for making spotter-to-shooter communication fast and easy. A fixed magnification of 33.5x gives you all the power you need, and a diopter ring and the ability to rotate the reticle to level it with the horizon line lets you customize your view.This eyepiece is specifically designed for use with the latest generation Viper HD 20-60x85mm spotting scopes - it is not compatible with the 65mm Viper HD modelsCompatible Models : Vortex V502, V503