This special design on the Yankee Hill A1 Style Flip Rear Style Sight has all the same features as the YHM-9680 model but features an A1 style windage wheel with a 1/2 M.O.A. windage adjustment. This Flip Rear Sight prevents accidental adjustment of the sight. To adjust, simply depress the plunger with a bullet tip and rotate the wheel. It is as easy as that!