A little maintenance goes a long way Keep your Ravin Crossbow in tip-top shape with this Serving And String Fluid. Lubricant and String Fluid helps keep your crossbow's string in working order and shooting flawlessly through any weather condition. Quick, easy to apply and should be used at least once a year for optimal shooting performance. Key Features Non-wax polymeric lubricant for applying to the center of your string Odor-free, waterproof fluid helps keep your crossbow in working order Apply String Fluid once a year or before use in weather below 32 F. Keeps your crossbow's strings maintained