sleeve and ball bearing fan

The ball bearing brand was NMB bearing imported from Japan.

The warranty for ball bearing fan is 30,000 hours but sleeve bearing just 10,000 hours.

Ball bearing has 5-8 years lifetime,sleeve bearing has 2-3 years lifetime.

Ball bearing fan noise level won't change for a long time term,but sleeve bearing fan noise level will grown as time goes on.Sleeve bearing is cheaper than ball bearing fans.
 

Optional function :Auto-restart ,Speed detection,Stoppage Alarm,Waterproof(IP55 optional), PWM function ,Temperature control etc.