they're crap. A bad way to turn spd pedals into awkward clipped pedals. Engagement is usually weird, and they have a compounded float problem where your foot naturally floats within the cage and the cage floats in the pedal. For less money (than this p.o.s. and cheapo spd pedals combined) you can get something like shimano M324's (I think) that have spd on one side and plat on the other w/o the kludgey plastic go-between.