The Bluebird 539007209 Aerator Chain Idler Sprocket Kit helps guide and maintain proper tension on the chain drive of compatible aerator equipment. This replacement kit works with the chain and sprocket system to support smooth movement and consistent power transfer during operation. Proper chain alignment and tension can help reduce unwanted movement, support reliable equipment perfo... https://www.wholetoolbox.com/bluebird-539007209-aerator-chain-idler-sprocket-kit/539007209.html