6pcs JEWELERS EYE LOUPE = 2ea 10x 30x + Dual Magnifying The set includes two 10x 21mm chrome loupes ,two 30x 21mm chrome loupes and two 10x&20x dual loupes The 10x power loupe has a focal distance of 1" (26mm) with 21mm dia lens size The 30x power loupe has a focal distance of 1/2" (13mm) with 21mm dia lens size The dual loupe is 10x power with 18mm lens size and 20x power with 12mm lens size, the strong magnifications with a mid distance of 1/2" Made of optical glass and protected when not in use by the swing-out chrome plated metal cover