Designed for mounting on DIN EN50022 Rail and compatible with HRFE/HMSA plug and socket connectors, Railbox features vertically sitting PCB to conserve space and optimize I/O connection density (17 poles per side on 5.00/5.08 mm pitch). Standard sizes include 17.5, 22.5, 35, and 45 mm, and enclosure is molded from UL94-V0 flame retardant material. Inserted between 2 halves of enclosure, expansion collar option allows additional space for cooling/mounting additional PCB.