The PC-n series (where n is wavelength λop, in micrometers, to which the detector is optimized) are high speed, ambient temperature photoconductive mode IR photodetectors. These devices can be optimized for the maximum performance anywhere from 2 to 12 µm. High performance and stability were achieved by using a newly developed variable gap semiconductors (HgCdZn)Te, optimized composition/doping profiles and improved surface processing. They are housed in rugged packages of reduced size and weight. Performance data are provided with each detector. The detectors are well suited for heterodyne detection of radiation at high frequencies due to a very short response time and to the perfect match to fast electronics. Custom devices with quadrant cells, multielement arrays, specialized packages, connectors, windows and optical filters are available on request.