The QCB has been cut from solid stainless steel bar stock for greater resistance to heat and burnout. The thread end of the brake tapers down to a .750" diameter. The brake comes with a selection of spacer shims to set the timing of the brake. The 3 holes should be at the 1 O'clock position when tightened into place. Tighten the brake into place using a round screw driver in the 1st slot closest to the barrel.