Here's some features of the Tiffen 82mm variable ND filter:

• Provides 2 to 8 Stops of Light Control
• Rotating Ring to Choose Degree of ND
• Eliminates Buying Many ND Filters
• Use to Create Blurs/Special Effects
• Use with Film or Digital
• Wide Outer Ring Reduces Vignetting
• Black Aluminum Filter Ring
• ColorCore Glass