The Halkey-Roberts (HR) valve wrench is used to tighten up valve that has come loose over time or to access the internal parts of the valve to clean or replace it. The HR valve wrench works on all HR style valves such as the Halkey-Roberts, Summit, or Gri Push-Push Valve. The HR valve is used on our Moki Kayaks, Platte Kayaks and Chasm Lite SUP.