The open bridge design of BX-3 Mojave™ Series binoculars is lightweight and ergonomic. Combined with its superior optics, you have performance that will impress the most serious binoculars users. Open bridge roof prism design Smooth focusing Cold mirror coated prisms Twist up eyecups Close focus distance of 10 feet Phase coated Diopter focus Fully multi coated lens system BAK 4 prisms