Celestron SkyMaster 15-35x70 Zoom Binocular (71013) Lower magnification allows the user to locate a subject more easily and then zoom in for a close-up view Multi-coated optics enhances sharpness of detail and crispness of color High quality BaK-4 prisms provide higher light transmission for better viewing in low light conditions Large objective diameter provides a comfortable viewing aperture at high magnification levels Long eye relief for more comfortable for all users; essential for those wearing eyeglasses while viewing Diopter adjustment allows for refinement of image to correct for any differences in strength between the users own eyes Tripod adapter included to mount the binocular on a tripod for prolonged viewing sessions or simply for increased stability while observing