... )3.Function instruction: a) Changing-speed pumps with a 3 speed knob control to change the speed(3Max-2-1min),min ... pump with control marked with Manual,Automatic,Stop.c) This electric product is airproof,all the rotating parts are in water when working,the ... shaft material isceramic,automatic water circulating,non-overloading motor,no external overload control required. d)The ...