New 3pc Jewelers Eye Loupes Set = 10X 30x + Dual Magnifier Loupe The 3pc jewelers loupes set includes one 10X 21mm chrome loupe, one 30X 21mm chrome loupe and one 10X&20X dual butterfly loupe. The 10X power loupe has a focal distance of 1" (26mm), the lens size is 21 mm diameter. The 30X power loupe has a focal distance of 1/2" (13 mm). The lens size is 21 mm diameter, it also include a small loop to attach to a neck chain or key chain. The dual butterfly loupe has 10X power lens with 18 millimeters and 20X power lens with 12 millimeters, the strong magnifications with a mid distance of 1/2" (13 mm) as well. Glass lens with metal body.