Double Magnifying Clip-On Watchmakers 10X 2 Eye Loupe. Double Lens Clip On Magnifier. This is a new double lens clip on magnifier. These attach to your eye glasses. Each lens is 3.3X and when combined they are 6.6X. The 3.3X lens has a focal distance of 3 1/2" (89 mm). Combined the 6.6X lens has a focal distance of 1 1/2" (38 mm) 10X Optical Headband. This is a new 10X headband eyeglass. Glare proof design. It's lighter than air construction makes this comfortable for lengthy wear. Band adjusts to fit all head sizes.