10X 15X 20X 30X Jewelers Loupe/Loop Magnifying Glass 10X & 20X Eye Loupe. This is a new dual power loupe made of optical glass with a swing-away, chrome plated case. This has become the standard style of loupe used in the watch making industry and is excellent for any application where magnification is needed. It is 10X power on one end and 20X power on the other. The 20X has a 12 mm lens and the 10X has a 18 mm lens. The 10X lens has a focal distance of 1" (25 mm) and the 20X lens has a focal distance of 1/2" (13 mm). Comes with a leather case. Both lenses are color corrected 30X Eye Loupe. This is a new doublet lens loupe made of optical glass with a round swing-away chrome plated case. The shape allows it to rest comfortably in the eye socket. This has become the standard style of loupe used in the watch making industry and is excellent for any application where magnification is needed. In terms of performance, it is second to none. It is 30X power and has a focal distance of 1/2" (13 mm). The lens has a 21 mm diameter 15X Eye Loupe. This is a new 15X plastic eye loupe. This pocket size loupe has distortion free lenses. The shape of this eye loupe allows it to rest comfortably in the eye socket. It has a focal distance of 3/4" (19 mm).