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How to upgrade & install M2 SSD (Lenovo Legion Y520 - Samsung 970 Evo plus) - YouTube
Lenovo on Twitter: "Hi! Thanks for reaching out. Good question, based on the parts listed in this article https://t.co/VsRcGVhGgI page 66 the Legion Y520 uses M.2 NVMe SSD. Kindly check this link
DYSK SSD 1TB LENOVO Legion Y520-15IKBA - Dyski i pamięci przenośne - Allegro.pl
Lenovo Legion Y520-15IKBM Specs and Details - Gadget Review
Lenovo Y520-15IKBN Notebook Model 80WK upgrade DDR4 RAM and M.2 2280 SSD 2019 - YouTube