New Triple Lens Folding Loupe. This is a new triple lens folding loupe. 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. Each lens is 5X, you can combine two lens for 10X or all three for a total of 15X magnification. The 5X lens has a 2" (51 mm) focal distance. The 10X lens has a 1" (25 mm) focal distance. The 15X lens has a 3/4" (19 mm) focal distance. It measures approximately 2 1/4" x 1 1/2" x 1" (57 x 38 x 25 mm) closed and 4" x 1 1/2" x 1" (102 x 38 x 25 mm) open.