Opteka 52mm UV HD Haze Multi-Coated Glass Filter for Nikon AF 24mm f/2.8D Lens | eBay
Amazon.com : 52mm Pro Series Multi-Coated High Resolution Digital Ultraviolet Filter for Pentax smc DA 50mm f/1.8 Lens, Pentax DA 18-55mm f/3.5-5.6 AL WR Zoom Lens : Electronics