Adapter for Smartphone-Holder that are usually fixed to venting Holes - this has an 8mm deep cross section to allow for a hook mount to be fitted. PM me for any requirements you need, I can make this bigger if needed.

This is a 3d printed design so please allow for some minor imperfections.

Measurements are

30mm hole diameter, 3mm thick cross section and 8mm depth on the cross section.

Hook and clamp mounts work perfectly fine, however compatibility with your mount is not guaranteed. THIS IS A MOUNT FOR THE VAN.

FOR deeper cross sections and a larger opening and the option for a mount, see: https://www.ebay.co.uk/itm/156137213328