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4 guaranteed-fit options
Guaranteed-fit promise
Every kit is matched to your machine's slots and checked against its published specs before we list it.
DDR3 · SO-DIMM · up to 1333 MT/s
1GB
Verified fit for your systemNot stocked right now. It's verified to fit — get an email the moment it's back.
Every option here is verified to fit this system. Muted means it fits too — we just don't stock it right now. Pick one to switch.
Software for your upgrade — matched to your Lenovo ThinkPad T420 Series T420.
Checks the drivers on your Lenovo ThinkPad T420 Series T420, installs the safe updates Windows offers, guides the rest to the official download — and confirms exactly which of the upgrades above your machine has room for.
Lenovo ThinkPad T420 Series T420 takes DDR3 SODIMM memory, 1 slot, up to 8 GB. Every option above matches those requirements, so it typically installs and runs without any firmware change.
“Spec match” means the module matches your system’s published specifications; it isn’t yet confirmed against a manufacturer tool.
Specifications reported for the Lenovo ThinkPad T420 Series T420.
Good to know
We've already verified which memory and storage upgrades fit this exact machine — they're just not in stock at the moment. Leave your email and we'll tell you the moment any of them is available again. Guaranteed fit, no wrong parts.