... fittings(such as couplings, belt-pulley, sprocket wheel and so on) must properly matethe shaft ,which prevents bearing from breakage ... in the productmanual, please fill proper category and brand lubricant. And then screw on thevent-plug; unlock the small cone-plug of ... these,reducer is already for starting up running. The proper brand and adequatelubricant oil is required, replacing oil in time ...