WTF is up with these olympic spinlock collars?

[GTC]

Below is a picture of the same kind of collar that I have except mine are York.
When I first got them I couldn't figure out how they were supposed to work and one of them didn't even fit on the bar, so I just threw them in the corner and forgot about them. There's no chance of olympic plates sliding off anyway, they're a tight fit.

But recently it was bugging me why they didn't seem to work so I tried them again. I want to know why it has that star-shaped spin lock thingy on it aswell as wing-nuts. The wing-nuts tighten the collar enough for it to stay on so what's the point of the spin-lock thing? It doesn't seem to make any difference.

Does anyone else have these kind of collars?

 

[pullinbig]

te spin nut goes against the plates and after you lock th ecollar down oyu can snug the plates up tighter. we use them in pling comps as well. we use them at the gym with out kilo plates. our loading charts include the additional 5k for the collars.