Sean, the Shelter 501 weighs 8 grams, and the compliance is 9cu. Shelter cartridges are made in Japan, by Mr.Ozawa, who used to work for Fidelity Research cartridges, back in the golden days of analog. Even in those days, FR was considered an alternative to Koetsu. Now Mr. Ozawa has moved on to form his own cartridge company called Shelter. Of course the other key player, Mr. Ikeda, has his own company too, but is going in other directions.