Sigma alarm fobs
 

Both my fobs have broken (as in wont go on my keyring) apart from ebay any 1 else no of anyone selling a spare, I'd be hoping just to swap the casing over and it would still work fine? Don't wanna carry it separately to my keys for long as I'm bound to loose it

^ I broke one of mine recently, If you find a good source I would be interested too :)

Ive Just drilled a 2.5mm hole thru the corner of the plastic, and it'd back on my keyring nicely. Saved me a few quid looking for a replacement