Xena XZZ6 Disc Alarm Lock: A Review

You could get anything up to 7.5mm in the slot.

Dunno if Clefty's arms differently or not but this one seems to rely on some metal breaking the plane of the sensor between the slot to set it. So I'm not sure how the ideas of using it on spokes or saddle rails would work, as I expect it would just hang there without the plane being broken, unless it were balanced carefully. It's ideal for my chainring though...

I would test it out more - but it wakes up the neighbours and scares the cats to death!

Yep, I've found it does need metal to break the sensor plane - my saddle rails will not work with it unless finely balanced. I'll update the original review.