ProChrono replacement diffuser pack includes four replacement guide wires and two replacement diffuser hoods, compatible with all ProChrono chronographs. Despite exercising caution, it is possible to damage the diffuser hoods or guide wires on your ProChrono chronograph. This replacement pack provides a convenient solution, ensuring your device remains operational. Suitable for use with air guns, firearms and airsoft guns. Replacement guide wires (4) and diffuser hoods (2) compatible with all Prochrono models, ensuring optimal performance and accuracy