“DSR” Hubs – for assembly with “AR” plate sprockets to make double-single of compound sprockets. Finish bore hubs have got standard keyway and 2 setscrews.
Ready Sprockets are an assortment of sprockets and hubs drilled 
and tapped for basic, READY SPROCKET HUB TYPE DSR convenient assembly with regular hex head cap screws. For No. 35 through No. 100 Chain, with share finished bore hubs to accommodate shaft sizes through 2-3/4″ diameter, plus a variety of square, hex, spline, and tapered crucial bores.