... .self locking 3.fast stop 4.good cooling effect NMRV series worm gear with output shaft:1) High quality aluminum alloy die cast ... gearbox 2) High accuracy worm gear and worm shaft 3) Less noise and lower temperature increase 4 ... :NMR025,NMRV30,NMRV40,NMRV050,NMRV063,NMRV075,NMRV090,NMRV110,NMRV130 NMRV series worm gear with output shaft