When the gauge pointer reaches the red area, please rise to the surface, inflate again to use. When using for the first time, please practice in shallow water.Due to the light and screen setting difference, the item's color may be slightly different from the pictures. Please allow slight dimension difference due to different manual measurement. The item "1L Oxygen Cylinder Air Tank Scuba Diving Equipment Breathing Bottle+Respirator" is in sale since Saturday, July 11, 2020. This item is in the category "Sporting Goods\Water Sports\Scuba & Snorkeling\Tanks". The seller is "homesale_estore" and is located in Shenzhen. This item can be shipped worldwide.