That L.A.S.T product - I've just found a reference from 2006 to it and confirmed that the previously linked PDF is dated 2006. Reference here:
Transponders for GA, a pain or a gain? « The Digital Aviator
Its maybe the one I'd heard about that didn't go anywhere / had problems?
There is also no reference to it on the named company's website.
Does anyone know anything from more recently?