Ideal for low-speed power transmission applications. Roller chain drives have the ability to handle high shock loads and deliver dependable performance make them the drive of choice for many applications. Dodge Taper-Lock sprockets require no expensive or time-consuming re-matching. Their taper-bushing mount automatically compensates for variations in shaft and sprocket machining tolerances. With Dodge Taper-Lock sprockets, there are no protruding flanges or screw-heads to take up valuable shaft space. Their compact design provides for more power-dense packages. Dodge Roller Chain Sprocket, Hardened Teeth Type ATL, 2-1/8 in Bore Dia, 4.52 in Outside Dia, 50 Chain, 21 Teeth, 4.194 in, 1.64 in Length Through Bore, Low-Carbon Steel No slip transmissionMinimal overhung load on shaft bearingsGenerally used in lower speed rangesLow cost, rugged performanceCompact designInstalls easilyFits shaft securelyAllows exact ratio/rating required for your operationInstallation-ready, right from box