The Insta360 Nano Mount tripod adapter (reviewed here) is now available for pre-order for $30 at Amazon. It says it’s ‘out of stock’ but you can order now and Amazon will ship it as soon as it becomes available.
If you don’t want to wait, it’s also available now from a reseller but at a grossly inflated price.
The Nano Mount is a dedicated tripod adapter for the Insta360 Nano (reviewed here), a 360-degree camera for the iPhone.
Hands-on preview of Insta360 Nano Mount tripod adapter