What is the stainless steel thing on a D lock for?

[Kermit power]

On the locking end of the D on a Kryptonite D lock there is a stainless steel collar right at the end of the D. Does anyone know what it's for?

It has worked loose on my wife's lock, which makes it a bit of a pain to close at times. If it's just there to attach it to a frame mount or something then I'll take it off, but didn't want to if it's an intrinsic functional part of the lock.

[mjcneat]

It is as you thought, a device to hold it to the frame.

[Kermit power]

Cool, thanks!