DECO buoy professional, Sopras sub

Deco buoy with a weight in the bottom part which helps to keep the buoy upright, 30m line, plastic clip?

Divers recommend: Attach a reel to this buoy with at least 30m line. Do not use the plastic clip provided. You can use a bungee band instead of the cover. Practice using the buoy in advance in safe waters. Some countries require every diver to use one of these.