B+W 46mm Circular Polarizing KSM MRC F-Pro Filter at KEH Camera
NiSi HUC C-PL PRO Nano 46mm Circular Polarizer Filter | NiSi Optics USA
Amazon.com : B + W Circular Polarizer Kaesemann - Standard Mount (F-PRO), HTC, 16 Layers Multi-Resistant Coating, Photography Filter, 46 mm : Electronics