This bundle includes 2 items: (1) Hannay #35 Drive Chain # 9912.0028 and (1) 5/8" Bore Sprocket # 35BS11-5/8. The parts included in this bundle will ensure your Hannay 1500 or 1800 Series Electric Rewind Hose Reels will run smoothly for your spraying or watering application. The 5/8" Bore Sprocket (# 35BS11-5/8) fits the Hannay 12V electric motor (not included) and # 35 drive chains. It has 11 hardened teeth so it will last longer than sprockets without hardened teeth. The sprocket ensures proper contact with the #35 drive chain, helping to prevent premature wear or breaking. The #35 Drive Chain (# 9912.0028) has 116 links with a connecting link and measures 43 1/2" long.