Caliber availability - 9mm, .40 S&W, .357 SIG; Upgraded, high-cut 1911-style beavertail grip tang for smooth draws; Undercut front-strap and reshaped, radiused trigger guard for the highest grip possible; Enlarged, integrated magwell opening for fast reloads-compatible with the latest generation Sig Sauer X-series factory basepads; Improved grip traction and increased grip pattern coverage with Wilson Combat's exclusive Starburst grip pattern; Frame reference serrations for support hand thumb or index finger positioning; Angled "Holster Cuts" on light rail to aid in snag-free, reholstering; Factory Sig Sauer magazine release, spring, and lock included; Compatible with all standard holsters; Compatible with all current production, X-Series basepads