Your lens is an important investment and well worth protecting. A ProMaster Basis Protection filter does just that while transmitting a clear, sharp image to your cameras digital sensor or film. Polished optical glass combines with a special multi-coating formula to achieve high light transmission and low light reflectivity. These features allow your lens to perform at its finest. All ProMaster Basis filters have the same size filter thread on the front and back. So, they are compatible with your lens cap, and they can be stacked with other, same-size filters. Basis filters represent a terrific value. They are optically excellent and affordable and deliver great results!