Abstract: A coupler for use with an excavator provides a hook with a mouth which receives a cross bar of an implement such as a bucket at an upper end. Towards a bottom end the coupler receives an extension through an opening. The extension is then retained by a pin through a bore in the extension and a bore in a body of the coupler. The mouth of the hook is provided with at least one wear pad which preferably extends along a substantial width of the mouth and is provided with adjustment members which can extend the wear pad into the mouth incrementally and/or to be tensioned against a cross bar with a selected amount of tension.