This GearWrench Flex Head Combination Ratchet Wrench 13 Piece SAE Set is designed with a 72 teeth ratcheting box end which needs as little as 5 degrees to move fasteners VS the standard box end wrenches with 30 degrees. Features flexible heads and a knurled side beam for ratcheting direction indicator. With Unique Technology on Box End it provides off- corner loading for better grip and reduced fastener rounding. Sizes included are 5/16", 1/2", 5/8", 15/16", 11/16", 9/16", 3/4", 13/16", 7/8", 1", 11/32", 3/8" and 7/16".