Those aren't "cache modules", those are static ram ICs.
As always - you never know if something is real or fake with chinese. I was buying old DRAM chips to repair ancient devices, and one of my three orders was fake, failing the acetone test.
I'd be cautious about 10ns option in DIP package. 20ns might be real, but right now mouser has only 12ns and those are in soj package, not dip. The 10ns DIP might be relabeled slower grade IC, if sram IC at all...

vstrakh wrote on 2023-11-10, 11:52:

Those aren't "cache modules", those are static ram ICs.

Forgive me for using the wrong term here, the plan is to use SRAM ICs as L2 cache, though.

I have since found a decade-old thread here on VOGONS (Super Fast 486 Cache - 10 ns) that I didn't want to necro, where somebody had ordered ICs that looked exactly like these in bulk, and had no trouble with them.
What I really wanted to know is my chance of receiving SRAM ICs that have the capacity printed on them, so my 486 will be able to cache its 64MB of RAM in write-back mode.

I guess I'll just have to try.

General consensus on VOGONs is that these chips have fake markings. To the best of our collective knowledge, there never were 10ns SRAM chips in a DIP package manufactured by ISSI. Nevertheless, you can expect to receive 5V 128k x 8 (1MBit) SRAM cache chips that can be used to upgrade your 486 system to 512 or 1024KB of L2 cache, but the chips are 12ns at best, possibly 15ns. Also, several people reported a dead-on-arrival rate of around 10%, so expect some failed chips. Returning them to AliExpress is likely not worth the hassle, so you might want to order a spare one with your initial order.

That's fair. The offer on Aliexpress is for packs of 5 anyway, so I'd buy 10, and if 1 or 2 are defective, that would still be fine for the 8 SRAMs I need.
Luckily I still have a 512Kbit TAG RAM, that should be sufficient for 1MB Cache.