Don’t forget that it’s a manual lens adapter. Works with full manual lenses. If your lens has no physical aperture ring, you cannot control it from your camera  

Answer: There is a front thread that allows another filter to be mounted to it, as long as it has the same aperture 

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. 

They are full size, but lite weight. We are very pleased with them. 

Front threads are available, allowing another filter to be attached to it, as long as it has the same aperture