Pod Air Filter 50mm Round Tapered Black Body and Cap with Red Foam Filter NEW | eBay
50mm Diameter, Red Dichroic Filter | Edmund Optics
Amazon.com : 49mm 7PC Filter Set for Canon EF 50mm f/1.8 STM Lens - Includes 3 PC Filter Kit (UV-CPL-FLD) and 4PC Close Up Filter Set (+1+2+4+10) : Electronics