it would effectively be a 120.10, as the 9 refers to the number of pawls. eg 1 pawl every 12 teeth, therefore 9 x 12 = 108. so the viz will have 10 pawls, and 120 teeth. freewheels are usually in multiples of 12, ie tensile 60 and 96 click, viz 72, echo 108, rockman 108.