It was an ebay special, 'Alembicase', I think they stopped making them, this was the only one I've been able to find. It's a very simple thing though, just an otterbox 3000 with the insert. The end wedges are spring mounted in the slot for a little resistance. In the centre it has a cut out for desiccant, I would imagine something to avoid if you have natural scales mind.
I think I might try to make one myself next time around though (as the collection grows), but rather than the plastic insert I might use solid foam with slots cut out with a larger gap at the tail end to make it easy to get out. That'll offer more impact resistance while travelling.