The DKM swab mandrel allows cups to be changed in just seconds. To disassemble, the mandrel is lifted 90° and the two sections of the joint are separated. The old cup can then be removed quickly and the new one slipped in place. There are no threads on the swab knuckles providing no threat of damage and galling. No tools are needed to change out the cups. Machined from one solid piece of bar stock, the DKM is tough, providing a large external bypass for fast falling, and uses the cup itself as a valve. As many mandrels and cups as desired may be run with the DKM. The upper mandrels joint provides reinforcement and preventing any type of spreading under load. While allowing the lower mandrel complete 360° swivel action. Designed with the swab hand in in, the DKM is the preferred swab mandrel of choice.