The filter thread size of Panasonic Lumix G X Vario 12-35mm F2.8 ASPH Power OIS is 58mm.
Below are links to the filters that we recommend you to consider for your Panasonic 12-35mm F2.8 OIS:
Read our detailed Panasonic Lumix G X Vario 12-35mm F2.8 ASPH Power OIS Review