SIG SAUER Pro P320 9mm Romeo X Pro XRAY3 Sights Barrel Assembly Black 3.9in. The factory-installed ROMEO-X PRO optic sits incredibly low to the slide so you can still use standard height iron sights when the optic is not in use giving you a consistent familiar sight picture Specifications for SIG SAUER Pro P320 9mm Romeo X Pro XRAY3 Sights Barrel Assembly: Manufacturer: SIG SAUER Gun Make: SIG Sauer Gun Model: SIG Sauer P320 Caliber: 9mm Luger Gun Frame Size: Compact Optic Cut: SIG Sauer Romeo 1 Finish: Nitron Fabric/Material: Stainless Steel Package Contents: SIG SAUER Pro P320 9mm Romeo X Pro XRAY3 Sights Barrel Assembly SIG SAUER Infinite Guarantee What firearm models does the manufacturer say SIG SAUER Pro P320 9mm Romeo X Pro XRAY3 Sights Barrel Assembly is compatible with? The manufacturer says that SIG SAUER Pro P320 9mm Romeo X Pro XRAY3 Sights Barrel Assembly is compatible with SIG Sauer P320SIG SAUER 8901568: Pro P320 9mm Romeo X Pro XRAY3 Sights Barrel Assembly Black 3.9in