The Star Tool by XS Scuba is a true save-a-dive tool for anyone diving with American (standard sized) products. For the installation and replacement of the most common standard sized hoses, it has ½?", 9/16", 5/8" and 11/16" wrench sizes as well as the most common standard sized hex key sizes; 5/32", 3/16" and ¼". It even includes a hand wheel tool if you need to work on a tank valve