Needle roller bearing is a special type of roller bearing which uses long, thin cylindrical rollers resembling needles. Needle bearings have rollers that are at least four times longer than their diameter. Needle roller bearings offer great rigidity and hence have the ability to handle a larger, more rigid shaft in a given application. These bearings have higher load carrying capacity than single row ball or roller bearings of comparable OD. Sometimes, to conserve space, the inner ring may be omitted and the needle rollers ride directly on the shaft.