The simple construction of the standard piston mechanism, and the strong material makes it highly durable and meets the divers trust. Movable downstream valve mechanism second stage is very good for maintenance. Standard Piston First Stage Large diameter pistons ensure the air supply that can withstand intense breathing. Ventury Adjustment Switch (VAS) prevents free-flow especially when entering the water, and assists maximum air supply when submerged. Standard camphobite mouthpiece 1st Stage Weight: 23.2 oz (630 g); 2nd Stage Weight: 5.6 oz (160 g); Total Weight: 36.6 oz (930 g); 1st Stage; High Flow Piston Type; 1HP Port/4LP Port; 2nd Stage; Downstream Valve Second Stage; Quick Connector Hose; Reversible Ventury Adjustment System; Fan Fobite Mouth Piece