Piantedosi Row Wing drop-in sculling rig for canoes or other small boats. Has Concept 2 oarlocks compatible with normal sculling oars. It really works well. There is more information, photos and videos here: https://www.clcboats.com/modules/catalog/product.php?category_qn=boat-gear&subcat_qn=rowing-gear-accessories&code=drop-in-sliding-seat-rowing-unit