K&F XB41 67mm Variable ND&CPL Filter 2 in 1 Function Nano Coating No “X” cross
Vignetting/X mark VERY visible at max setting
The entire upper right part of any picture I\'ve shot using this filter has a large black overcast on it. My blue sky would become black.Will be exchanging this for a fixed ND or go with GOBE or Polar Pro. Build quality is fine tho.