Yes, Legion 5 Pro has two NVMe PCIe 3.0 2280 SSD slots, the second slot is empty and has a pre-installed heatsink with a thermal pad. (I installed Samsung 970 Evo 1TB
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Can't Install M.2 SSD in Legion 5 17" : r/Lenovo
lab501 » Review – Lenovo Legion 5 15ARH05 – AMD Ryzen 7 4800H – ENGLISH Version
Inside Lenovo Legion 5 (15) – disassembly and upgrade options