The Vortex Optics Sheltered Wings Talon HD Binocular 10 x 42 (SWTLN4210HD) lets you see their every move. It features an XR fully multi-coated lenses that increases light transmission. The HD glass has an extra-low dispersion that creates an impressive resolution, giving you high definition images, every time. It's a fogproof and waterproof gear and it provides secure, non-slip grip external protection. The exterior has an ultra-hard, scratch-resistant coating which protects it from such damage, oil and dirt. This product is also compatible with a tripod adapter, allowing you to mount this on your window car for your convenience. You can adjust the focus of both barrels all at once and even adjust it for different user's eyes. The function button is on the right eyepiece.