correct ring for a recessed can fixture

I just installed a Halo H5 ICAT, type 1C recessed can ceiling light fixture. I was sold a Halo 300P ring for this fixture at LOWES. For the life of me, I can't figure out how to snap the light socket from the can into the bracket of the ring. The metal snap is actually wider then the bracket in the ring. Do I have the correct ring? If not, can you tell me what its designation should be?