Replying to Rossi Axial 110 Question

Hey, I've got a set of Rossi Axial 110 bindings that I bought second hand.  I was wondering if anyone knows what the deal is with the swivel action of the heel part is.  Does it do anything special any other binding doesn't do?  Better ejection or what?  Also, proper correction of my terminology would be appreciated.  It also seems that after every day I go skiing the swivel becomes more loose.  Is this an experimental binding from Rossignol, because I don't seem to  see this feature on most other bindings.