Sig air proforce M17 airsoft pistol is similar in Look and feel to the U. S. Army issued P320- M17 9mm pistol and features a polymer frame and metal slide with full blow-back action. The proprietary drop magazine holds 21 rounds of 6mm polymer or biodegradable BBs. An adjustable Hop-Up feature creates spin on the BBs for additional stabilization in flight, resulting in increased distance and accuracy. A Picatinny accessory rail allows for quick and easy mounting of a laser or tactical flashlight.