These kits (2X and 4X) include an alternate lens, extension tubes, and a new calibration tool along with instructions for installation. The 2X Macro optical imaging kit (p/n 100-12-MACRO2X) reduces image area from 6.8 x 5.1mm to 4 x 3mm. The focal length changes from 4 inches to 1.6 inches. The 4X Macro optical imaging kit (p/n 100-12-MACRO4X) reduces image area from 6.8 x 5.1mm to 2.2 x 1.6 mm. The focal length changes from 4 inches to 2.3 inches.