Vortex Optics Diamondback 10x42 Roof Prism Binocular Roof prism full-size 10x42 binoculars provide 10x magnification through a 42mm objective lens. VIP Unconditional Lifetime Warranty means Vortex Optics will fix or repair at no cost to the customer, no questions asked. Multi-coated optics and phase corrected prisms Waterproof and fogproof protection Rainguard, tethered objective lens covers, comfort neck strap, and deluxe custom-molded carry case included in the box. Field of View: 345 feet/1000 yards|6.6 degrees Close Focus: 5 feet Objective Lens Diameter 42 mm