This ND64 WMC 100x100mm Filter from Benro is a 6 stop neutral density long exposure filter designed to reduce all different wavelengths of light for an even 6 stop reduction in light. This allows your shutter speed to be slowed significantly, which is particularly useful when photographing water and tides, or when a dramatic effect is desired.
The WMC abbreviation is short for Waterproof Multi-Coating, which as well as being anti-reflective, makes this filter water and oil repellent and fingerprint and scratch resistant.