Ratcheting box-end needs as little as 5 degrees to move a fastener. Has an adjustable set screw, for desired head tension. The flex head tilts up to 180 degrees at any interval. GearWrench products are warranted for life to be free of defects in material and workmanship The flex head has a spring washer design, which provides continuous head tension. The sleek beam is serrated for the sure grip and the feel for which way it needs to be turned.