Abstract: An improved remote control master-slave manipulator of the type by which an operator working on one side of a protective barrier wall may perform work on the opposite side of that wall. The improved manipulator is characterized by a unique power assist tong system permitting increased handling capacity. It has a rotating counterweight system for improved balancing of the manipulator in its "Y" motion forwardly away from the operator. It has means for translating linear motion into rotary motion for transfer through the barrier wall and retranslation into linear motion. The wrist joint assemblies are remotely removable, replaceable and interchangeable as are the tong assemblies.