Fits all 1/4-inch socket-type torque wrenches for use with the Prestacycle Bicycle Bit Set. Prestacycle's bits cost 1/10 the price of buying socket head sets to meet all the requirements of bicycles. Using bits allows you to perform initial installation with Prestacycle's reversible mini ratchet - then leave the bit inside the job - remove the mini ratchet - and connect your torque wrench onto the bit to finish final tightening.