ive seen the one on ideations whippet at a show and seemed a decent bit of kit,it certainly didnt look to bulky, which was what my concern would have been on a small rabbiting dog.
i would imagine that it would be hard to try and replicate the strength of the big collars in the smaller ones ,being as their more fiddley to construct.
an no im not his arse licker or ever met him, ive just only had a collar off him for missus bulldog.