The 52mm ProND EX 3-Filter Kit from Hoya includes three ND filters, all featuring front and rear 62mm 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. Kit Includes: PRO ND EX 8 (3-stop) PRO ND EX 64 (6-stop) PRO ND EX 1000 (10-stop) Carry Pouch Thanks to ACCU-ND technology, the image undergoes no negative effects from color shift that may occur due to low-quality materials, poor manufacturing QC, or issues with leaking of the Infrared band of the light spectrum. HOYA's exclusive ACCU-ND technology achieves equal reduction of the light in visible and IR spectrums. As a result, the photographer doesn't experience issues with color shift when using HOYA ND filters in different shooting conditions. The filter is mounted into a lightweight, precision-milled aluminum frame. It includes front filter threads so you can attach additional filters or a protective lens cap. Filter At a Glance Glass Type: Hoya Clear Multi Coatings: Yes Hardened Top Layer: No Anti-Static: No Frame Construction: Standard Profile / Aluminum Front Filter Threads: Yes