First, K&F Concept ND2-ND400 lens filter allows changing shutter speed based on the effect you want with the best sensibility and the same aperture. Second, K&F Concept ND2-ND400 lens filter allows creating a blurred background with a large aperture while the shutter speed remains the same. Third, K&F Concept ND2-ND400 lens filter is designed to prevent overexposure and maintain image purity and quality at the same time. *Like a zoom lens, the variable nd filters are suitable for multiple shooting situations. If you're looking for perfect image quality, a fixed ND filter is recommended. 

K&F Concept 

This will work on any 82mm lens. 

All the K&F concept lens cap is screw-on cap, but the outer frame of lens hood features with no thread, so once attach them together, will be easily fall off, we suggest to attach the lens cap directly to lens instead of lens hood. 

No, the lens cap can only be used with K&F Concept variable ND filters.