The park tool fr 5gt cassette lockring tool with 12mm guide pin is designed specifically for use when removing and installing cassette lockrings from thru axle hubs park tool fr 5gt cassette lockring tool with 12mm guide pin features part of a comprehensive range of freewheel removal tools the fr 5gt is designed specifically for use when removing and installing cassette lockrings on thru axle hubs utilizes a 12mm guide pin to stabilize