The MHW-3 Three Axis Water Hydraulic Micromanipulator was Narishige’s first water hydraulic micromanipulator specially designed for patch clamping. Its water hydraulic system has a lower coefficient of expansion than an oil hydraulic system, and allows precise movement. A 1:5 cartridge is incorporated to minimize drifting. The large, rigid driving unit enables fine movements and coarse manipulations and a sturdy ball joint is also used. Installation is made more rigid by securing attachments with a double adaptor, eliminating direct attachments to the bar. The drum type control unit has a large handle for precise operation and high linear repeatability. Overall, design considerations are focused on precision movement and stability over long periods of time. The MHW-3 Three Axis Water Hydraulic Micromanipulator set the standards for subsequent models of micromanipulator for patch clamping.