SanTan Tactical STT-15 Pillar Lower/Upper Receiver Set Features The SanTan Tactical STT-15 Pillar Lower/Upper Receiver Set was engineered from the ground up to solve a problem most AR-15 receivers never address namely true ambidextrous operation. Every Pillar AMBI set ships with a full suite of ambidextrous controls including the bolt release so a left-handed shooter gets the same manual of arms as a right-handed shooter without aftermarket parts. Machined from 7075 billet aluminum the set is built to the tightest tolerances SanTan Tactical can hold which keeps the fit between upper and lower consistent and snug. That consistency matters for accuracy and reliability since a loose receiver fit can introduce play that affects both. Finished in Olive Drab Green anodizing the STT-15 set gives builders a durable corrosion resistant surface that stands up to range use and field conditions alike. Because the set accepts multiple AR-15 caliber platforms builders can configure it around the cartridge and upper combination that suits their intended use whether that is a home defense carbine or a precision range gun. The ambidextrous design makes the STT-15 a strong foundation for a duty competition or training rifle meant to be shared or used interchangeably by right and left-handed shooters. For builders who want a rock-solid true AMBI receiver set in a distinctive Olive Drab Green finish the SanTan Tactical STT-15 is a dependable starting point. SanTan Tactical STT-15 Pillar Lower/Upper Receiver Set Specifications Manufacturer: SanTan Tactical Model: STT-15 Pillar Lower/Upper Receiver Set Type: Lower/Upper Set Action: Semi-Automatic Caliber: Multi-Cal Color: OD Green Finish: Anodized Material: 7075 Billet Aluminum Available At: GrabAGun