Stupid RCA Jack Question

I am replacing my amplifier, as my first was stolen. There are RCA jacks running from the receiver to the hatch. The tips of the jacks have a post sticking out, with what look like clips that would fit around the perimeter of the female plug. They also appear to screw on such that it tightens those clips. When I try to connect them, however, they are totally loose. The only thing I can think of is that when the receiver was stolen, there were small rubber disks laying in the hatch - do they somehow tighten that connection? If this is the case, where would I pick up replacements?

Any help is appreciated.

when they stole it they probably messed up the connectors, try using some pliers to make the surrounding part on the male plus smaller in diameter so it has fricition against the female counterpart, or just replace the cable.

They were damaged (the tightening cover was missing), though for those reading this post for reference, a couple dabs of Superglue did the trick.