The New HOYA HD Mk II series features 16 layers of anti-reflective coatings with HOYA's water repellent and stain resistant coatings making filter maintenance easy. The UV & Protector incorporate chemically hardened optical glass which provides excellent lens protection against accidental damage and the CIR-PL features High light-transparency UV-absorbing polarisation film for faster shutter speeds.The PROTECTOR filter is designed for constant use and is recommended for shielding your valuable lenses from expensive front element damage that could be caused by knocks dirt or scratches.Features:16 layer (both sides) anti-reflection coating with superior water & oil repellent characteristics for easy maintenanceChemically and thermally hardened extra-clear optical glass that is 4x stronger compared to normal optical glass to achieve excellent protection abilitiesLow profile frame with front thread to attach lens caps or other filtersPress mount technology to retain glass tightly i