Shimano Thunnus CI4. Lightweight and the power to stop big fish. Not a sentence you are used to hearing! Seemingly against the laws of nature. Thunnus takes a page from our Bicycle division using Carbon materials in high impact situations. Thunnus CI4 is a response to all the anglers out there in love with the ease of use and functionality that wanted the reel to shed some weight. Thunnus CI4 is up to 7 ounces lighter than its predecessor without sacrificing any power. Quite the opposite!! Due to new drag systems for the Main Drag and the Baitrunner drag Thunnus CI4 is the most efficient live bait spinning reel on the market with unmatched adjustability for fishing any bait in any condition as well as the smooth stopping power that this generation of Thunnus will be known for.