These are Hynix 2GB 2Rx8 PC2-6400S-666-12 modules (part number: HYMP125S64CP8-S6).
Specifications: These are 2GB DDR2 SO-DIMM (200-pin) modules running at 800MHz.
Historical Context: These modules were manufactured by Hynix (now SK Hynix), a company with a significant history in the semiconductor industry. Originally founded in 1983 as Hyundai Electronics Industries, it became Hynix in 2001 and was acquired by the SK Group in 2012, eventually becoming one of the world's leading memory manufacturers.
Usage: These modules were standard for many legacy laptops and mobile workstations from the mid-to-late 2000s. They are ideal for buyers looking to restore or upgrade vintage machines that utilize the DDR2 standard.