Flex-Head Ratcheting Wrench KitFlex Head Ratcheting Kit This is what I'd call a secondary kit. You probably already have your main set of wrenches (the ones you reach for every day). This set comes in when you're working in tight spaces where a fixed head just won't work. The 90 tooth ratchet gives you a 4 swing arc, so you don't need much room to actually get work done. The flex head lets you angle the wrench to reach around obstructions, and the ratcheting box end is just easier