The 28/24-spoke RD-220s are FSA's entry level wheels. They are a more orthodox design than FSA’s quirky RD-600 with its third hub flange.
The 220’s rear hub has a larger diameter flange on the left to balance the difference between left and right spoke tension associated with a dished wheel; the right hand spokes are straight-pull and slot in sideways to the hub.
FSA uses conventional spoke nipples concealed inside the rim to cut drag but you’ll need to remove the tyre before using the special tool supplied to true them.
The unusual spoke pattern combined with the thinness of the left hand rear flange places a lot of stress on the elbows of the left hand spokes, and though we had no problem with our test models, we have seen breakages on previous wheels used by heavy riders. They’re strong enough for lighter riders though.
The rims are on the heavy side for climbing steep gradients, but the axles turn smoothly on cartridge bearing hubs and the skewers are by far the best we’ve seen on a set of wheels for this kind of money.