Franklin Armory's patented Binary Firing SystemA(R) (BFS(TM)) is now available for your GlockA(R) 17 Gen3! The new G-S173 allows you to select between semiautomatic and BinaryA(R) modes to provide reduced split times and tighter groupings. Like all BFS(TM) triggers the release round can be cancelled by simply switching back to semiautomatic while the trigger is depressed. Plus you'll always know which mode you're in without having to come off your target with the integrated back plate mode indicator. Prefect for defense sporting and recreational use.Features: - Easy to install- Fits GlockA(R) 17 Gen3- Selectable Semi and BinaryA(R) (pull and release)- Integrated mode indicator- Optics ready (custom adapter plates sold separately)- Front and rear tritium night sights- High-tactile front and rear serrations- Anti-glare top stripe serrations Binary Trigger Operation: Position 1 - Semi - Fires 1 round per pullPosition 2 - Binary - Fires 1 round on pull and 1 round on release