BONES WHEELS 99A Street Tech Formula™ wheels ride smoother and faster on a greater range of terrain, without loosing the unique grip, slide-ability and characteristic bark of our original Bones  103A SFT. Street Tech 99A will improve your skating if you are not always riding super smooth concrete. They make it more fun to skate a wider range of terrains by cushioning your landings, gripping, sliding, and rolling MUCH easier on rough pavement…without flat spotting.