FNH 16s & 17s Armorer's Tools allow for barrel changes, bolt work, and trigger installation to be performed properly Tools include: 16s & 17S Barrel Straightness Gauges, Ejector Removal Tool, Ejector Installation Tool, and Trigger Module Mounting Axis The Barrel Straightness Gauges ensure proper alignment of the barrel with the receiver when reinstalling 16s or 17s barrels The Ejector Removal Tool allows for 16s and 17s ejectors to be easily removed from the bolt body The Ejector Installation Tool allows for 16s and 17s ejectors to be reinstalled with ease The 16s & 17s Trigger Module Mounting Axis ensures that the trigger module is instal Mfg: Brownells SPECS: Black oxide finish. 16s and 17s Barrel Straightness Gauges - Heat Treated to Rc 45-50. Machined from A2 Tool Steel. 16s/17s Ejector Removal Tool and Installation Tool - Heat Treated to Rc 30-35. Machined from 4140 Steel. 16s/17s Trigger Module Mounting Axis - Heat Treated to Rc