We prevailed on designer Richard Nichols to put his name on this one - and what a holster it is - a fresh interpretation of the trailing holster he helped popularize. On the Nichols Avenger(TM), a dual-plane open muzzle suits both standard and shortened barrels and the double reinforced holster mouth has adjustable tension at one end and a double-thick belt slot at the other. An integral belt loop on the back cooperates with the outboard belt slot for stability and concealability. A full time strapless design is made for the professional with "the need for speed!" NOTE: Not compatible with red dot optics NOTE: If you are ordering a holster for a Glock Generation 4 weapon, please keep in mind that we manufacture our holsters for the factory standard version without any of the back strap attachments. Contact our customer service for more information on holster fits for Glock Generation 4 weapons.