Features: Made of high quality stainless steel, anti-rust and durable. High pressure air pump by hand, 53cm/20.9in length air pump tube. Simple to operate, making diving become easy, no need to carry large scuba. With a pressure gauge on it, you can know when to stop inflating. Portable and practical, essential accessory for diving. Specification: Material: Stainless Steel Color: Shown as pictures Air Tube Length: Approx. 53cm / 20.9in Connector Diameter: 3.1cm / 1.2in Connector Length: 9cm / 3.5in Weight: Approx. 2840g Package List: 1 * High Pressure Air Pump (with Connector and Air Tube) 1 * Wrench(Size: 14.8 * 5 * 0.25cm / 5.8 * 2.0 * 0.1in) 2 * Packages of Accessories 1 * Manual Note: 1. High-pressure air pump, in the process of air inflating due to up and down friction, resulting in fever, this phenomenon is normal. 2. The phenomenon of oxygen cylinder respirator can't be inflated: firstly, when oxygen cylinder respirator is delivered, it does not contain gas, secondly, check the high-pressure pump before inflating the high-pressure pump, assemble it according to the instructions, install the gasket rubber ring, tighten the exhaust valve, and then inflate it. This product is different from oxygen pumps such as basketball, volleyball. Effectively, please be patient to inflating for two or three minutes before the pressure gauge will change. It takes three men to inflating about 16 minutes for each oxygen cylinder to fill up. Within 3000PSI, it is within the normal range. Over 3000PSI may burst (please don't inflating too full). 3. Oxygen cylinder head and body should be checked for tightness, good connection and not standing above the oxygen cylinder when inflating. Be careful not to inflate the oxygen cylinder to a certain pressure. Oxygen has certain impact. Please pay attention to safety. 4. When the pump is finished, please notice that it is dangerous to twist the exhaust valve of the high-pressure pump and suddenly pull out the connecting port between the pump and the oxygen cylinder. 5. Please note that the new type and old type of this product will be sent randomly, and make sure you will not mind before ordering. ​.