The unarowhals scuba diving tank is made of aviation-grade aluminum and uses an upgraded breathing valve core to provide you with a better user experience. At the same time, the diving tank has a three-layer filter device that can effectively prevent dust and impurities from entering, making the inhaled gas cleaner. All products are DOT certified, so you can use them with confidence. Its maximum diving depth is 33 feet, and it can be used as a backup air source for deep diving within a depth of 100 feet. Small diving tanks are suitable for underwater exploration, boat cleaning, emergency rescue, backup air source, etc. The use time of a 0.5L diving cylinder is about 5-10 minutes, and 1L is 10-15 minutes, depending on your diving depth and breathing rate. Of course, no matter what capacity of diving cylinder, there are four ways to inflate: 1. Local diving shop, unarowhals diving cylinders meet DOT standards and can be inflated at local diving shops. 2.Use the scuba adapter, 8mm inflation port, connect to a standard large diving tank, and your diving cylinder can be inflated in 4 seconds. 3.4500psi air compressor, 0.5L diving tank inflation, about 11 minutes to complete. 4.High pressure hand pump. This is an alternative inflation method. You need to provide manpower within about 30 minutes.