A connector for connecting power or control systems infrastructure such as for example subsea infrastructure, said connector comprises a male component and a female component, the male and female components comprising cooperating mating surfaces and means for locking the male and female components together, the locking means being retractably mounted within one of the male or female components but extendible from that component into the other of the male or female components to lock the two components together against axial and rotational movement while providing a snag free release when the locking means is in the retracted position. The means for locking includes pivotal levers with free ends that are to enter recesses of the male component and that are to be held in locking position by a moveable control coupler. An electrical coupler located within the female component is to be raised to engage a corresponding coupler on the locked in position male component.