Howshot 67mm threaded mount base is suitable for 58mm flat ports (Recsea RX100 or RX100Mk2 housings). It will protect the ports securely without rotating. Or easily attach wide angle or macro lenses with 67mm threaded, like INON UWL-H100M67 wide angle lens or UCL-330, UCL-165M67 ,SubSee +5/+10 and etc. close-up lenses to have super macro photos.
Recsea WHS-RX100Mk II
|Wet Lenses||M67 (67mm) Thread|