3-Speed High Velocity Commercial Floor Fan - 20" - FE-50TDO

this fan design is the only way to go when you wanna move some air- even on the low setting - a bit of advice ; it generates such propulsive force that the whole unit will actually slide backwards off a slick surface and that is on low setting ... so make sure it is stable before you walk away from it ... is a bit noisy , not like a mechanical sound , just the fact that the blade is high - velocity , like the name says ;-) no info on maintenance ; only had it a couple daze ...killer fan for sure