disc lock

[stephen.stallebrass]

Not sure I would recommend xena, I bought the xx14 but it hasn't faired well. It looks solid but the internal alarm plastic module is very fragile. I dropped mine while taking it off the disc, only about a foot but it fractured the plastic tabs internally and the alarm wouldn't stop sounding.
A bit of superglue fixed it but I wont be able to replace the battery when it packs up.

There is a solid metal version... I've had both. The one you describe is also a bit dodgy with regard to the key too, had one snap off in the lock once.

This is the one I use:

This one sucks ass: