Japan Aviation Electronics Industry (JAE) had developed the JL10 Series, a MIL standard screw mating and one-touch locking hybrid circular waterproof connectors, to offers to a wide range of customers as an interface for industrial equipment. The one-touch lock mating allows for more efficient operation than a screw mating type, as the reliable mating does not loosen even in a vibrating environment and prevents any type of ingress. These products are used for industrial equipment common with circular connectors conforming to *MIL-DTL-5015 standards, but more recently there have been an increasing demand for miniaturization while maintaining robustness, improved operability and reliability of conventional products. By adopting an original contact arrangement that differs from the MIL standard, we have been able to develop new products that are more compact than the conventional JL10 connectors.