Package Included:1 x First Level Pressure Reducing Valve(S400+)1 x Medium Pressure Air Hose1 x Second Level Breathing Valve1 x User Manual2 x Fluorine O-Ring Specifications:Weight: 882gModel: PV-002Material: 6061 Aviation AluminumMax. pressure: 3000PSI / 200bar / 20MPA(can't exceed)Medium Pressure Pipe Interface Model: 3/8-24UNFOxygen Cylinder Interface Model: M18x1.5Medium Pressure Air Hose Length: Approx.71cm/27.95"First Level Pressure Reducing Valve Height: Approx.9.5cm/3.81"Second Level Breathing Valve Height: Approx.9.7cm/3.74"Box Size: Approx.33*15.7*10.4cm/15.03*6.92*2.67" Application:1L oxygen cylinder(Not included) + medium pressure tube + second Level breathing valve Features:- Compact portable lightweight ,easy to use.- Use with a 1L oxygen cylinder(not included),underwater breathing time can reach 10~15 minutes.- Made of  Aviation Aluminum material ,surface plating,hard and corrosion resistant.-The pressure gauge has a luminous function, and the underwater 80m is still very clear.- The dial design is clearly visible, and the pressure value is accurately identified at a glance.- When you bite the Mouthpiece and prepare to inhale, you can gently press the top pressure relief valve to release the pressure drain water.  Tips:Do not use this article before reading and understanding the instructions and notes.1. This product is suitable for recreational diving within 10m. Do not attempt to use it as an air supply in deep water.2. This product can be used as a backup air source for recreational diving within 30 meters.3. This product is suitable for waters above 10℃ Celsius.4.Inflate the product before use and check for damage or leakage. Never use items that are damaged, leaking or showing signs of performance error.5. The maximum filling pressure of this product is 3000 PSI or 200bar,And can only fill the compressed air that the human body breathes.6.Keep the product in a cool, dry place away from direct sunlight.Do not store in a car trunk or high temperature, or put it in fire.7. When the gauge pointer reaches the red area, please rise to the surface, inflate again to use.8.Emergency equipment must be used in an emergency. This product does not provide protection in the event of danger.9.When using for the first time, please practice in shallow water.