Nige,

It's not Hassy sunglasses, it's actually Zeiss sunglasses with something like "T-coating" (note the missing * from T). I have a pair of the regular sunglasses and have had a few pairs of RayBans, etc.

There is something about the quality of the Zeiss glasses that is different (and better). Almost like looking through Cokin filters vs. Heliopan's.

They're somewhere between 200-500 US dollars. But, worth every dime.