The 82mm NanoPro Magnetic Circular Polarizer Filter from Haida comes with an adapter ring that screws onto your lens. With the ring screwed on, you can magnetically attach the polarizer filter and easily swap it out.
The adapter ring has both front and rear 82mm threads and accepts standard threaded as well as Haida magnetic lens caps on the front. It can be kept on your lens at all times. The polarizer filter features glass optics with a top coating that protects against water, oil, dust, fingerprints, and scratches. The filter and adapter together weigh approximately 1 oz.