<p>A lock for a cam-and-groove coupler comprises a collar member positionable around the cam-and-groove coupler. The collar member comprises at least first and second wall portions. The first wall portion is positionable adjacent the first lever arm of the cam-and-groove coupler to prevent movement of the first lever arm to an unsecured position. The second wall portion is positionable adjacent a second lever arm of the cam-and-groove coupler to prevent movement of the second lever arm to the unsecured position. The lock further comprises at least one projection extending inwardly from the collar member and configured to engage the cam-and-groove coupler to prevent the collar member from sliding off of the cam-and-groove coupler. At least one securing member is coupled to the collar member and configured to releasably secure the collar member around the cam-and-groove-coupler.</p>
