Double Width Large Caliber Wire-EDM machined for perfect fit, and unmatched precision. (Smooth Type - Low Profile)USTS Double Width .50 BMG and Large Caliber Scope Rings (Low Profile) These 4140 steel rings were specifically designed for the heavy-hitting recoil of the .50 caliber BMG round in our double width configuration. After extensive research and development, we have overcome the problems seen in most of the high-end rings designed for the .50 caliber BMG round. On our double width .50 BMG rings, we found that the use of TWIN nuts, together with six HOLOKROME cap screws on each ring is essential to securely affix the delicate telescopic optic properly. This minimizes torque-induced damage to the optic, from the heavy recoil of the weapon system. US Tactical Systems .50 BMG Ring Set Features This particular set of rings are 0.940" from the base to the centerline of your scope ring, and compatible with objective sizes up to 45mm. (Low Profile) They fit the standard MID STD 1913 (Picatinny) rail and include a parkerized matte finish. The US Tactical Systems steel rings feature two 100% perfectly square cross-cut bolts, precision machined to snuggly fit the Picatinny rail cross-cut slots. This allows maximum contact with the MID STD 1913 cross-cut slot for a solid mount that will not move under extreme pressure or large caliber recoil. Each Scope Ring Cap also features genuine HOLOKROME Hex Screws because only the best will do. Inferior fasteners are what most scope ring manufactures try to pass, even in high quality rings! Not familiar with HOLOKROME? Learn more about them here. For more versatility with several scope and optic configurations, we have also included perfectly matched pair of 1-inch inserts with every set of rings. The inserts are so you can mount your scope if it is either a 30mm scope tube, or the more available 1-inch scope tube configuration. The 1-inch inserts are “lipped” on both sides to eliminate movement. This is the last set of rings you will ever buy, and once you get your hands on them...the only brand you will ever consider! Backed By Our Lifetime Guarantee! An ideal mounting system secures your optical device to your firearm as low as comfortably possible, with the fewest parts necessary. More parts equal more chances for something to go wrong. Our designs have minimal parts while still preserving the features expected from a high-end scope ring set. The weakest link in a shooting system is your scope mount. The finest rifle and scope combination is rendered useless without rugged and reliable rings and bases. Some well known manufactures will not tell you what materials their rings are even made of, or don't even know. Call them up and ask! The USTS rings are the only Wire-EDM rings machined from one solid billet of 4140 chrome-molybdenum steel. The result is a highly accurate, super-strong steel ring set made to last a lifetime!