soft rubber that does not hurt your stereo microscope Three different sizes: 33mm / 1.3 ' ' Diameter, 18mm / 0.71 ' ' Height Suitable for 32-35mm lens, 36mm / 1.42 ' ' Diameter, 18mm / 0.71 ' ' Height Suitable for 34-37mm lens, 33mm / 1.3 ' ' Diameter, 30.7mm / 1.21 ' ' Height Suitable for 32-35mm lens Eyepiece cover design to reduce, and better protect your eyes When working under a microscope, this rubber eyepiece guard can protect the eyes from outside light, and see objects more clearly Help create the perfect distance between the eye and the reach An essential microscope accessory to protect your stereo microscope and also your eyes, Manufacturer: Tsophreniq