K&F Concept 77mm 4pcs NANO-X Magnetic Lens Filter Kit UV CPL ND1000 W/ Bag

【Magnetic Quick Swap System】Changing filters is now an easy one-handed operation with no more screwing! Using the Magnetic UV or empty adaper ring as the base, then you can add CPL and ND1000 Neutral Density Filters in 1 second.

eBay