SkyMaster 15 has a lower magnification to allow the user to locate a subject more easily and then zoom in for a close-up view. Multi-coated optic lens to enhance the sharpness of detail and crispness of color. High quality BAK-4 prisms to provide higher light transmission for better viewing in low light conditions. Large objective diameter to provide a comfortable viewing aperture at high magnification levels. Long eye relief to help provide comfort for those wearing eyeglasses while viewing. Diopter adjustment allows for refinement of image to correct the differences in strength between the users own eyes. Tripod adaptor included. Water resistant. Limited lifetime warranty. Weight: 53 oz.