Sightron’s S-TAC 1-6x24 SR1 Service Rifle Scope was specifically designed for modern sporting rifles chambered in .223 and 5.56. All models in the S-TAC family are equipped with Sighttron’s ExacTrack W& E System that provides proper alignment between the adjustments and the erector tube by maintaining the same constant and accurate point of pressure at zero or extreme adjustments, resulting in zero drift. The large oversized tactical knobs are easy to adjust in any weather conditions and are resettable to zero. The new internal zero-stop mechanism provides a tactile and audible positive stop for dead-on zero setting. The S-TAC 1-6x24 SR1 Service Rifle Scope also features an exclusive optical design to reduce chromatic aberrations, improve color accuracy, and deliver excellent light transmission. Optical quality is further enhanced with the exclusive MC-333 Multi-Coating Technology – a 3 Layer multi-coating process that employs a new and revolutionary lens coating technology applied to both surfaces of the lenses for excellent anti-reflection performance and the highest light transmission. Features of the S-TAC Riflescopes: ExacTrack W& E System – eliminates drift Exclusive Optical Design – minimal chromatic aberrations, improve color accuracy, deliver excellent light transmission MC-333 Multi-Coating Technology – a 3 Layer multi-coating process that employs a new and revolutionary lens coating technology applied to both surfaces of the lenses for excellent anti-reflection performance and the highest light transmission Sightron S-TAC 1-6x24 IR AR1 Riflescope 26022