The norbar professional adjustable mushroom head torque wrenches are fitted with norbars industrial style of ratchet using the principle of offset pawls these ratchets feature a robust tooth pattern and a narrow engagement angle meaning that the wrench is easy to use in tight spaces the square drive features a finger grip on the top the mushroom head that assists with running down the nut until resistance is met the square drive can also be removed and replaced in the opposite direction s