It's the X-pro 100x150mm Hard GND8 Square Filter, a professional-grade photography tool designed for capturing stunning images in challenging lighting conditions. Ideal for scenes with contrasting light and dark areas, such as seascapes, skylines at sunrise or sunset, and mountainous landscapes, this filter is an essential tool for every photographer's kit.Crafted from Agc optical glass, this durable filter boasts a double-sided 28-layer coating, including an anti-reflective green film. This innovative coating technology effectively minimizes surface reflection, reducing glare from long-exposure lenses and ensuring superior image quality.The X-pro 100x150mm Hard GND8 Square Filter is encased in a KandF Concept Pro Protective Frame, a design that has been recognized with the prestigious if Design Award and Red Dot Design Award. This robust frame safeguards the filter from accidental drops, providing an added layer of protection for your investment.