The 77mm ProND EX 3-Filter Kit from Hoya includes three ND filters, all featuring front and rear 77mm threading, so they can be stacked together. The ND8 filter reduces the amount of light passing through the lens by 3 stops, the ND64 by 6 stops, and the ND1000 by 10 stops. These filters feature Hoya's ACCU-ND technology, which prevents color shift to allow consistent image quality. The filters are made of glass and the filter rings are aluminum. A carry pouch is included that holds all three filters.