HOLSTERS WILL FIT: STI/SVI | 4.40" BBL | With Optics + Light | Staccato P Duo W/ Vortex Viper or Venom, Trijicon RMR, SRO, Deltapoint Pro, Holosun 407, 507, 508, 509, or Burris Fastfire and Inforce APL, Olight PL-Pro or Valkyrie, Nightstick TWM-350, TWM-350S, TWM- 850, TWM-850S, ITI M3, TLR-1, TLR-1HL, Surefire X200, X300, 300V, or X300U