As header, came across it a year or so ago and hung onto it, but no longer have storage.
Is currently deflated, but holds air fine. It is red/orange.
Is the A5 model, and is a huge buoy. Sells for about £100.
Link below to manufacturer:
https://www.polyformus.com/c-8-a-series.aspx
Looking for £20 collected from Worthing, West Sussex. Can perhaps deliver to Portsmouth/Soton during daytimes.