FRNKLN 17-50000-BLK BFS G-S173 GK17 G3 BINARYFranklin Armory's Binary Firing System (BFS) is now available for Glock 17 Gen3. The new G S173 allows you to select between semiautomatic and Binary modes to provide reduced split times and tighter groupings. Like all BFS triggers, the release round can be cancelled by simply switching back to semiautomatic while the trigger is depressed. Plus, always know which mode youre in without having to come off target with the integrated back plate mode