Featuring easy installation and high performance in an optical ASIC caliper package, the KX21 series modular kit encoder uses set-screw mounting and provides an installation tool for concurrent air-gap and electronics alignment. The aluminum disk/hub assembly is secured to a stationary shaft using the carbon-steel set screw. In addition, the device is claimed to have, at 0.03", the widest air gap in the industry. It is available in diameters of either 1.5" and 2.1" and provides jitter-free outputs and resolutions up to 1024 pulses per revolution. List price for the rotary kit encoder is $100 with typical configurations and in small quantities.