A logging tool and method of its use

A logging tool or togging tool sub 10 for downhole use comprises an elongate cylindrical body 11 supported by one or more pivotable arms 12. The arms are moveable between an extended position and a retracted position. In the extended position a part of each arm protrudes beyond the exterior of the cylindrical body 11 to provide exposed landing surfaces that are engageable with one or more landing surfaces 21 of a further component such as a drill tube 19. The landing surfaces may be a an cut-out 13 or shoulder 21 in a drill pipe or other component. In a retracted position, the arms 12 do not protrude externally of the cylindrical body 11. The pivotally connected arms allow the tool to become engaged with a landing surface, or may allow the tool to go beyond a drill pipe landing ring.