Special Features:

Per manufacturer- it is not a pulley but a tension set or soemtimes called a taper-lock ring. The assembly has a pattern of bolts- as the bolts are tightened it pulls an inner ring tight around an axle or round shaft; the part is within the driving and steering group; part is within the chain sprocket

Properties:

A clamping element consisting of a tapered inner and outer ring in closed design for mounting different types of hubs on shafts and axles. Inner and outer ring constitute a pair of rings. These rings are firmly pressed against each other by tightening bolts which are not part of the clamping element, and subsequently moved on the taper thus producing radial forces for fastening the hub on the shaft by friction fit.