Octo 300 Self Cleaning HeadThe Octo Skimmer Neck Cleaner has been designed to keep the collect cups neck free of bio organic build up. By doing this you ensure your protein skimmer is running at its best. The blades periodically wipe the inside of the neck and remove any build up. The bio organic matter which causes the skimmer to foam and stick to the sides restricts the collection of skim mate within the cup and reduces its effectiveness, the neck cleaner ensures your skimmer