Rival Arms Two Piece Magwell for Sig P320 Full Size & Compact Black. It is constructed of CNC-machined aluminum with an anodized finish. Specifications for Rival Arms Two Piece Magwell for Sig: Manufacturer: Rival Arms Color: Black Finish: Anodized Fabric/Material: Aluminum Gun Make: SIG Sauer Gun Model: SIG Sauer P320 Package Contents: Rival Arms Two Piece Magwell for Sig What firearm models does the manufacturer say Rival Arms Two Piece Magwell for Sig is compatible with? The manufacturer suggests that Rival Arms Two Piece Magwell for Sig is compatible with SIG Sauer P320Rival Arms RA-RA70S201A: Two Piece Magwell for Sig P320 Full Size & Compact Black