About the B+W 40.5mm XS-Pro Digital HTC Circular Polarizer Käsemann MRC Nano Filter
The B+W HTC Kaesemann C-Pols, in F-Pro and thin XS-Pro mounts, are the latest polarizers from B+W. HTC stands for High Transmission Circular Polarizer, with a 1-1.5 stop loss, as opposed to up to 3 stops with standard polarizers.