The muzzle in the Kel-Tec P17’s 3.8" barrel is threaded, and the gun includes both equally a one/2x28 TPI threaded barrel extension plus a thread protector (proven). The bilateral thumb security levers swing up in to the Secure position and down, revealing bright purple warning dots, into the hearth placement. https://kel-tec-p1764703.worldblogged.com/27417406/5-essential-elements-for-kel-tec