The Leupold BX-4 Range HD Gen 2 TBRA(R)/W 10x42 fuses Leupold's DNAA(R) engine and ballistics software with the optical performance diehard hunters and shooters demand. Now you can spot and range targets without switching optics. It has a maximum range of 4,000 yards on reflective targets and 2,000 yards on trees. Its high-contrast red OLED display delivers crisp readouts in any light, while edge-to-edge HD clarity reduces eye strain for longer glassing sessions. Elite Optical System - offers excellent dawn-to-dusk light transmission for a bright image when it matters most, elite-level glare reduction in harsh light, and the resolution and clarity that diehard hunters and shooters demand.TBR-W - True Ballistic RangeA(R) / Wind (TBRA(R)/W) technology provides ballistically calculated ranges for extremely accurate shots at longer distances and steeper angles. It can also generate a hold point for a 10-mph wind at a 90-degree angle out to 800 yards.Bow Mode - With its TRIG function, Bow Mode is an excellent "set it and forget it" feature that is simple to use and accurate out to around 70 yards and for angles less than 20 degrees. This function is ideal for Western spot-and-stalk hunters and tree-stand hunters, providing 10-ring target level accuracy.Last Target - guarantees that the rangefinder identifies the most distant target along the laser's trajectory, preventing inaccuracies caused by adverse weather conditions like rain, snow, or fog.Line of Sight (LOS) Mode - calculates the distance to a target in a straight line, regardless of any incline or decline.Interchangeable Form-Fit eyecups - come in three different sizes, allowing you to customize your viewing experience based on your preferences. Choose the winged eyecups for blocking out stray light, opt for the medium eyecups for all-around comfort, or select the low eyecups designed specifically for use with glassesArcher's Advantage mode - uses your arrow weight, arrow velocity, and peep height to deliver precise range calculations made for shooting at steep angles or over long distances.Leupold's ergonomic design - ensures their products are slim, lightweight, and fit well in your hands no matter what size they are.Easy-grip Standoffs - Easily locate the buttons with easy-grip standoffs, even through thick gloves. Prevents accidental activation and battery depletion.Tripod Ready - A built-in 1/4-20 rotatable tripod adapter port makes it easy to mount to a tripod.Smooth Focusing - features an extremely smooth focusing system for fine adjustments.Leupold pioneered modern waterproof and fogproof technology using advanced internal gasses and sealing methods that withstand extreme temperatures and elevation changes, so the internals of the optics stay moisture free and crystal clear for life.