Harsh environment connector with rotating end seal assembly

A harsh environment connector has first and second connector units which each have at least one contact chamber in which at least one contact is located. Seal assemblies at the front ends of the respective contact chambers include seal members which rotate about the longitudinal axis of the connector as the units are mated to allow contacts of one connector unit to pass through aligned seal openings and into engagement with contacts in the other connector unit. Each seal assembly has a seal clamp member and the seal and seal clamp members are relatively rotatable during mating and de-mating between a first position when the units are unmated in which the seal openings are clamped shut by the seal clamp member and a second position when the units are mated in which clamp portions of the seal clamp member are offset from the seal openings.