Alternately, DC fans with the omniCOOL™ system that utilize the enhanced bearing design include a “-C” or “-CF” suffix on respective part numbers. The omniCOOL system’s enhanced bearing design incorporates specialized grooves on the outside of the bearing that assist with circulation of lubricant around the shaft. This improved circulation also works to reduce friction and build-up of lubricant, leading to more efficient operation and longer life expectancy compared to traditional designs. While the magnetic structure of -V series fans and the enhanced bearing of -C or -CF series fans both minimize the cost-performance tradeoff of traditional sleeve and ball bearing designs, the -V series does offer a longer life expectancy than the -C or -CF series. On the other hand, the enhanced bearing of -C or -CF series fans are more economical.