1 1/4  to 1-1/8 steer tube reducer headset
converts frame headtube from 1 1/4-inch steer tube to 1-1/8-inch steer tube
fits most Cannondale & other frames that have a straight 1-1/4 steer tube fork  
headset cups outside diameter is 37mm(top & bottom)
has sealed bearings

this headset will not work with a tapered fork

 To make sure this headset will fit your frame measure the inside diameter of your frames head tube(top & bottom) in millimeters with calipers if possible but a tape measurer will also work.(See pics 6 & 7) If you get a measurement between 36.8mm - 36.95 this headset set will fit your frame

please ask questions if your not sure this headset will fit your frame