Abstract: The coupler has, in several embodiments, a compliant-link having flexible or pivoted fingers that engage a groove in the inside of a lower link in at least three places. The groove appears much like a bearing race. The compliant-link is retained inside of an upper sleeve that is attached to an upward-extending post. The lower (engaging) link is attached to a downward-extending post. The fingers are able to disengage from the groove under spring action and thus a sufficient applied moment will cause disengagement. Disengagement does not cause anything to break. Assembly, or reassembly, of the coupler may be performed without extra parts or tools. In several of the embodiments, the decoupling moment may be manually adjusted using less moment than the resultant decoupling moment. The decoupling moment is essentially independent of azimuth. The coupler is particularly suited to being used with rural type mailboxes, and warehouse buffers and supports.