First Stage. Piston design. The DFC system (Dynamic Flow Control) guarantees a high-quality and accurate regulation of the air flow. First stage has 5 ports; 4 low pressure and one high pressure. Comfort grip knob and shock resistant cap. Body is made of high-strength nickel and chrome-plated brass with a matte satin-finish surface. Second Stage. Dual-material second stage body construction (patent pending). Exceptional light weight and ideal buoyancy under water, for superior comfort. Integrated VAD by-pass system, for breathing that is always easy and natural under all conditions. Coverplate with mesh-grid design (patented). CE UNI-EN 250 Certification.