The Field Optics Research EyeShield fits scopes with eyecup diameters from 1.1 to 1.46". The EyeShield is a flexible molded rubber material that connects to the eye piece of the spotting scope. The EyeShield envelops eyes in darkness, preventing ambient light from causing lens glare. EyeShield also block out wind, rain, snow, dust and peripheral distractions. EyeShield is a must-have for everyone who uses spotting scopes.