How To: Upgrade the RAM and SSD in a Lenovo Legion Y520 Laptop | Wyatt Fleming
Lenovo Community
Lenovo a 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