Abstract: A mechanism for housing a writing or marking cartridge includes means for retaining the cartridge in a retracted position within the housing and means for extending the operative end of the cartridge beyond the housing and releasably locking it in place for use. The housing comprises an open end through which the operative end of the cartridge is extended, and a closed end which houses a retaining means for securing the cartridge in the retracted position. The retaining means includes an annular collar which houses a flexible center section having fingers adapted to capture the support end of the cartridge. The means for extending the cartridge comprises a telescoping helical coil member frictionally secured on its outer end to the interior of the housing and on its inner end to the cartridge.