Abstract: A downhole coupling mechanism for use in downhole tools that find application in wells exploited by a hydraulic refracturing process. The downhole coupling mechanism connects first and second tubular sections via a tensile load arrangement of wires located in complimentary grooves, a torque arrangement of interlocking lugs and notches on opposite ends, and a seal arrangement. The downhole coupling mechanism provides a thin walled coupling where a screw-threaded connection could not achieve the required tensile load, torque and sealing properties needed. Embodiments of a thin walled anchor and packer including the downhole coupling mechanism are described.