AI biathlon sling has no cuff. TAB biathlon sling has cuff but is a bulkier, more padded rig - I have both.
Problem is, for me, that using any biathlon sling interferes with wearing a ruck - you need to wear the ruck over the slung rifle, which is a PITA. I shot the SHC this year using the biathlon sling with a TYR COMA harness, which is clear in the spine area, so the rifle could be slung and pouches and pockets could be used on the sides, but this was also a PITA - hard to get the rifle on and off with a bunch of pouches L & R.....
My current setup is a regular TAB sling with cuff, rifle slung diagonally accross the chest, which is good with a ruck.