This is a great float for targeting barbel in fast shallow water. Theres a lot more to it than just barbel fishing though as its also the perfect float for chub and indeed any fast water situation where buoyancy and visibility are the key requirements.
Always use this float with a DH In-Line olivette rather than a bulk of shot as its much less tangle prone this way and casts much better too. Below the olivette, which is fixed about 18 inches to two foot from the hook, I use one shot, which is usually a No4 or a No1.
For big baits like pellets, meat, corn and bread it’s often better to just have the bulk about a foot to eighteen inches above the hook with no drop shot.

RECOMMENDED SILICONE RUBBER
TOP 3mm to 8mm mixed
BASE 2.0mm