Prior Scientific Inc. offers the H122ROT high-precision focus drive designed to fit most upright and inverted microscopes with standard coarse and fine focus. To prevent cable twisting and windup, the device is designed with a rotating connector. It provides motorized focus step sizes as small as 0.002 μm for very fine and precise Z-movements. It is available with optional probe-style encoder feedback to provide accuracy and repeatability for researchers using 3-D imaging and deconvolution techniques. For larger movements when speed is required, it can be driven at speeds of up to 20 revolutions per second.