1High quality aluminum alloy housing 2high quality synthetic lubrication oil 3high quality Tin bronze worm wheel 4NSK bearing Model size:25,30,40,50,63,75,90,110,130,150Speed ratio:7.5,10,15,20,25,30,40,50,60,80,100 High quality aluminum housing from 025-090,iron cast from 110-150High quality Tin bronze worm wheelhigh quality 20MNCr5 worm shafthigh quality NSK bearingshigh quality synthetic ...