Marumi 77mm Variable ND2 Filter – ND400 DHG
ND2 is 1 stop and ND 400 is about 8 2/3 stop. So the first marking is ND2 follow by ND4, ND8, ND16, ND32, ND64, ND100, ND256, and ND400
Key Features:

Adjustable ND2-ND400 light control
Ultra thin screw thread black aluminium frame design
Japanese optics and original light reducing material construction
The Marumi DHG Vari ND2-ND400 filter allows continuous variable light adjustment through ND2 to ND400. With one single filter the user can create different light densities by rotating the filter in the same way as a Polarising Filter works. The filter enables the photographer to use lower shutter speeds under very bright sunlight without altering the colour tone of the picture.