Manual Worm Gear w Chain Get 2m of usable chain. The chain is 4m total with 2m of hang. Our low friction Worm Gear never needs to be lubricated and with a higher impact plastic material wheel and galvanized chain/housing won’t rust or corrode.The innovative swiveling chain guide allows for tension free chain pulls from directly below the apparatus or at an angle. The drive ends are 0.75 inch and have holes drilled through them to secure the drive or roll-up tubes mounted on ends.