This is a clearance price, and no further discounts are available. This filter is essential for astrophotography, which blurs bright stars to make constellations stand out clearly from the many stars. In astrophotography, there's a desire to avoid soft effects on landscapes like mountains and buildings, so this product is set to approximately half the soft effect of the conventional Pro Softon (A). For more details, please refer to the manufacturer's website, etc. I purchased this to take astrophotographs with a digital camera and wide-angle lens I previously owned, but it has been stored in a dehumidified storage unit without being used. I am selling it because I no longer have a use for it.