A complete RRS / RRSC Type coupling depends on the size.
For RRS090-RRS110: 2 Standard RRS Hubs, & 1 Spacer Assembly (consisting of 2 snap wrap spiders w/o ring, 2 collars with screws, & 1 spacer).
For RRS150-RRS225: 1 Standard RRS Hub, 1 Standard RRSC Hub, & 1 Spacer Assembly (2 snap wrap siders w/o ring, 2 collars with screws, & 1 spacer).