This Compact Metric Hex-Tool includes six of the most commonly needed 2 mm, 3 mm, 4 mm, 5 mm, 6 mm, 8 mm metric hex key (aka allen key) sizes, plus phillips and flat screwdrivers forged from chrome-vanadium steel within a very compact plastic housing. In scuba applications, this tool is useful for installing and removing the yoke inserts found in convertible DIN valves, as well as fitting the IP adjustment opening found on some types of first stages. Dimensions: { 2.5 in L x 1.4 in W x .75 in D } { 6.4 cm L x 3.6 cm W x 1.9 cm Weight: { 4 oz | 113 g }