The HDF float is a weighted float made for the purpose of being able to cast further without using excessively heavy weights. The shape and added flaps allow the float to go further than what would usually be possible.
It is recommended that this product is used during the day.
The floats come in three sizes: 6, 10 and 15. You match the float with 20g, 30g and 50g respectively (+- 5g).