Nisi filters offers a complete square filter system for all of today's popular lenses. It's perfect for landscape photographers looking for a high quality, easy-to-use system to realize their creative vision. Nisi square filter systems are available in the 100mm size for most threaded wide angle lenses, The 150mm size for popular Super-Wide lenses including the Nikon 14-24mm f/2. 8 or Tamron 15-30mm f/2. 8, and the 180mm size for the new Canon 11-24mm f/4L or Sigma 12-24mm art. All NiSi square filters are made of high definition optical glass and feature double-sided waterproof Nano coating, an IR protection coating, Ultra low color cast, and a low reflective index.