In May 1997 Lexmark introduced the Optra S 1250, 1650, and 2450, a new line of network printers offering speeds of 12, 16, and 24 pages per minute (ppm) respectively, and a maximum resolution capability of 1200 dpi for each model. A few months later, Lexmark added two more printers to the line, the 1620 and 2420, offering 16 and 24 ppm speed, as well as 1200 dpi capability. Both models are based on the same 4059 engine as the previous three printers.

In 1998 Lexmark added to the Optra S line yet again with the introduction of the 1255, 1625, 1855, and 2455 models. These newest printers offered more processing power than preceding Optra S offerings. Many options including duplexing, mailboxes, stackers, and Lexmark's impressive MarkVision management software made these printers premier choices for corporate workgroups. The printer management software was the first to tell the end user the yield the cartridge in the printer, the pages printed, the toner level ranging from full to empty and the approximate number of pages remaining.

The entire line of printers used the same cartridge, which was available in standard capacity (7,500 pages) and high capacity (17,600 pages) yields. The two cartridges were essentially the same with the exception of the toner weight (200 vs. 500 grams) and the physical characteristics of the encoder wheel.

From a remanufacturing standpoint the cartridge is mechanically simple to remanufacture. However, there are a few design features that make this cartridge somewhat unique - the location of the PCR in the printer, a PCR cleaning assembly incorporated into the wiper blade stamping, the toner metering system, and the encoder wheel that is a key element of the printer's toner sensing technology.

Unisys UDS-9712