The female coupling half includes: a body, a plurality of locking bars, a spring, a locking ring, and, a cam. The body includes a plurality of grooves, an exterior, and an internal longitudinal bore. The cam, locking ring and locking bars are movable between first and second positions. The cam in the first position permits the locking ring in first position, urged by the spring, to force the locking bars to a first position in the grooves of the body and to extend the locking bars into the internal longitudinal bore locking the male and females coupling halves. The cam in the second position engages and forcefully urges the locking bars to a second position in the grooves toward the exterior of the body and the locking bars urge the locking ring to a second position further compressing the spring.