The kit consists of several bags of parts - all nicely made and all present and correct to assemble the kit, just as you'd hope. There are no instructions and that's not a huge issue but you will want to spend a little time thinking it through before you start assembling because there is a wrong way to do it which will end with you taking it apart and rebuilding it the right way. Maybe that's part of the fun?
Anyway, once assembled, it is an unobtrusive and high-quality kit, though I also added the Quadlock anti-vibration kit to mine (which bolts straight in, just as it should) because Quadlock say it's recommended for the iPhone 13 Pro (and Max). This is because the undamped vibration can potentially damage the in-body image stabilisation system on the phone, so give it some thought.
I also added the relevant rain poncho for the phone case because this is the UK after all...