The Okidata 400e was introduced in August 1993 and the 800e in May 1995. Both models use the same supplies SKUs that include a drum unit (rated at 20,000 pages) and a separate toner cartridge (rated at 2,000 pages).
The 400e/800e printers are not to be confused with Okidata's 400/800 models as they use drum and cartridge units with a different design - the 400e/800e system utilizing a PCR-based charging system, while the 400/800 uses a corona wire system. Supplies cannot be interchanged successfully.