Bicycle Mechanics - Plastic collar on U-lock

OK, so it's not technically a bicycle question, but it's bike-related. What is that little plastic collar for? It's sort of a shelved cone shape and sits at the open end of one side of the 'U'. Mine keeps sliding off and I'm thinking of taking it off permanently...

Thanks

:) What is the brand name and model of your u-lock.This would help!:)

Post a picture!

You can see the plastic bit I'm talking about on the lower right.

Did you buy the lock or is it a second-hand one?

If it is indeed a Kriptonite lock, the sleeve on the lower right is actually an adaptor that fits with with the optional bracket they sell to attach the lock on the bike when you travel. You may see the bracket here (first article)
http://www.kryptonitelock.com/inetisscripts/abtinetis.exe/PublicArticleDetails@public?artid=2695&atf=products_item&pgrp=20

Basically, you unlock the lock, pass the right leg of the lock (as shown on your photo) through the hole of the bracket, then lock the lock back in place and voilà, your lock is secure onto the bike. [The only "problem" vs your illustration is that the "U" part of the lock would be down, not up.]

The collar is normally tightened via a small Allen bolt and nut. When it's tight enough, the collar doesn't move and doesn't even rotate.


BTW, one aspect that puzzles me: I bought my lock without the collar. It'S only when I bought the braket that the collar was given to me.

Regards,

kryptonite has two bracket systems. the one with the collar is what comes as the "aftermarket" kit and on the evolution series (and maybe the new york series, i cant remember). the kryptolok series comes with a bracket that clamps onto the shackle, making it unnecessary to open the lock to put it on the bracket.