P/N 55Y9021
More about this type of keyboard...
The Model M6-1/ThinkPad pointing stick keyboard family were a wide range of ThinkPad keyboard assemblies and discrete keyboards. "True M6-1s" from the '90s were buckling sleeves keyboard assemblies produced by Lexmark, Maxi Switch and Key Tronic and were an evolution of the Model M4 family. These buckling sleeves M6-1s were succeeded by a myriad of scissor-switch keyboards produced by many OEMs including Acer, Alps, LITE-ON and NMB. These successors, however, mostly lacked the official M6-1 designation. Almost all M6-1s featured a TrackPoint pointing stick, however and specifically, the discrete SK-8845CR keyboard uses a Synaptics TouchStyk pointing stick instead. These 'classic' ThinkPad keyboards were axed by Lenovo around 2012, however, IBM and later Lenovo's x86 server division continued to have SK-8845CRs produced well after 2012.