Hole center diameter:35MM. 
Fits:most Chinese 50cc,70cc,90cc,110cc,125cc ATVs and Dirt Bikes,such as TaoTao, Buyang, NST, BMX, Coolsport, Kazuma, Sunl, Roketa, AIM-EX etc.
lIt may also fits on a Honda CRF or XR50, 70, 90(using big bored carb) and most pit bikes,depends upon individual case.
lIt will allow your motor bike to do deep breath and generate much more power,prolong the engine Life.
lManufactured to exact measurements to meet or exceed OEM specification.
lOur high quality parts are the exact replacement part for many Chinese manufactured brands and models of Chinese Mopeds,Bicycles Bike and Scooters.
lSample image shown,please check pictures above for details and specifications.