Originally Posted by Litespud

flip-flop track/single-speed/fixie hubs - the “step” is for a left hand threaded lock ring to hold the fixed sprocket on. The other side is for a single- or multi-speed freewheel (this won’t take any cassette). It has QR-compatible hollow axles, but they look too long to use QR skewers - think these are sized for track nuts.
Man, how much of a hurry were you in......?😟