Scopecoat safeguards your optics from dust, dirt, dings, scratches, and moisture with our high quality neoprene nylon laminate; This neoprene product is not designed to be completely WATERPROOF, but is extremely water resistant. Your Scopecoat BREATHES and actually draws moisture and condensation away from your scope; Scopecoat protective covers fit a variety of optics. When choosing the right size Scopecoat, measure the overall length of your scope in inches and the objective lens in millimeters; Scopecoat stretches to custom fit to your optic while providing maximum protection. Our standard Scopecoat cylindrical covers can stretch approximately 1 to 1 .5 inches beyond the stated size; 12.5in x 42mm