“DSR” Hubs – for assembly with “AR” plate sprockets to READY SPROCKET HUB TYPE DSR create double-single of compound sprockets. Finish bore hubs have standard keyway and 2 setscrews.
Ready Sprockets are a variety of sprockets and hubs drilled and tapped for simple, 
convenient assembly with regular hex head cap screws. For No. 35 through No. 100 Chain, with stock completed bore hubs to support shaft sizes through 2-3/4″ diameter, and also a variety of sq ., hex, spline, and tapered key bores.