Preventive Measure & Warning: 1.This product is suitable for recreational diving within 10 meters.Do not try to use it as in waters. 2.This product can be used as a backup air source for recreational diving up to 30 meters deep. Before using this product, you must obtain the training and certification of the accredited institution for scuba diving technology. The use of this breathing apparatus by unauthorized personne at depths exceeding 10 meters may cause danger. 3.This product is suitable for use in waters that above 10 degrees Celsius. 4.Recommended maximum speed is 15 metres per minute (the last 6 meters need to be 6 meters per minute). 5.Do not carry products with signs of damage, leakage or undesirable performance. 6.The maximum filling pressure of this product is 3000PSI, and it can not to use filled that gas with oxygen content 40%.Please use clean and dry compressed air, do not expose products above 160 degrees Celsius environment or open fire. 7.After filling the air, the pressure must be released first. 8.Please practice in the shallow water area for the first time. The use of this product requires two or more people to accompany you. 9.When the gauge pointer is close to the red area, stop diving. It must be inflated before it can be used again. 10.Store the product in a cool, dry place, avoid direct sunlight, car luggage, or extreme temperatures. 11.This product is a high precision product, please do not disassemble and assemble this product at will.Disassembly of this product may cause damage to the product. 1. The 0.5L oxygen cylinder allows the diver to stay 1-10 meters underwater for 5-12 minutes (depending on individual lung capacity and depth of diving), perfect for beginners. 2. Supports 3 types of inflation: Manual high-pressure Inflatable pump, switch, electric inflator.(Inflator pump is not included) 3. Uses 6061T6 aluminum material and meets the manufacturing standards for diving equipment. 4. Comes with a pressure gauge to show how much air is in the diving tank. 5. Fitted with an ergonomic silicone mouthpiece. 6. Press and hold the top to vent the pressure inside the bottle. 7. and portable design, it can be taken on board after twisting the breathing valve. Specifications: Breathing Oxygen Cylinder Capacity: 0.5L Oxygen cylinder weight: 1300g Maximum Capacity:3.0 Cu.Ft / 85 Litters Length: 13.4inch / 34 cm Diameter: 2.25inch / 5.7 cm Maximum Pressure: 3000PSI / 200BAR / 20MPA Breaths: 57 Max. dwell time underwater: 12mins Pumping time:7-10min Colour: Yellow Material: aviation aluminum Size: 34 x 5.7cm Package Contents: 1 x Oxygen Cylinder Only the above package content, other products are not included. Note: Light and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.