A d-lock is a rigid metal lock shaped like a letter. Fit a d-lock.
The rigid shape leaves no room for a tool to be worked into it, which is why it beats a cable. A d-lock is heavy, and everybody who has lost a bicycle carries one anyway.
1nound-lockA rigid metal lock shaped like a letter.
“The d-lock cost a fifth of what the bicycle had.”
d-lock is a lock.
Practised in Cycling