DEAD-HOLD BDC RETICLE Customized hashmark design helps eliminate guesswork on holdover and windage corrections. Good for hunting/shooting at varying ranges where estimating holdover is a concern. Fully multi-coated with anti-reflective lens coatings for brighter views Nitrogen gas purging with o-ring seals delivers fogproof, waterproof performance Shockproof construction withstands recoil and impact One-piece aircraft-grade aluminum alloy construction, for one inch Riflescopes