Cache SRAM ICs for 386, 486, Pentium machines. All are 15ns used, tested pulls. Beware of fake SRAM on eBay/Aliexpress. The 64K*1 are rarely-used chips of model CY7C187, equivalent to TC5561P. Make sure to get the correct types of SRAM for your board. For example, for 1MiB cache, a board often needs eight 128K*8 ICs, and one 64K*8 IC. Check your motherboard manual or TheRetroWeb or TotalHardware99 etc for the required cache ICs and jumper settings, or enquire. Photos are just examples. Model number and brand may vary.