.Chainsaw SpeedCut Nano Sprocket, C Spur, 325LP-7T, for Echo CS 2511T SpeedCut Nano sprockets are designed to work with 80TXL saw chain and TXLN guide bars as a system to optimize performance on electric and small gas chainsaws. They are economical with good wear resistance, have a one-piece design that must be replaced as a complete unit, and normal replacement schedule is every two chain loops.