In reply to Otis:
It's a new take on an old school bit of gear (Cassin something or other). Harder to place than a big cam, and probably more likely to fall out but significantly cheaper.
I got one out of curiosity, and have even placed it. Once.
The improvement on the original is basically the string and button mechanism, that allows you to cock the thing at the bottom of the pitch & place it one handed.
I need to climb more offwidths so I can use it again.
