Can confirm the Western Digital SN520 256GB NVMe drive is compatible with the Deck : r/SteamDeck
SDAPNUW-512G Western Digital PC SN520 512GB Pcie 3.0 X2 M.2 2280 Nvme SSD SDAPNUW-512G-1032 M.2 SSD / Solid State Drive - Newegg.com
Western Digital PC SN520 SDAPTUW-512G-1012 DP/N 0FFD82 512GB M.2 2230 NVMe SSD | eBay
Western Digital SN520 256GB M.2 2280 NVMe SSD Drive – Electronics Outlet: Open Box New & NEW Electronics, TV's, Computers, Tablets, Printers and Networking Gear
Western Digital PC SN520 Series 256GB TLC PCI Express 3.0 x2 NVMe M.2 2280 Internal
Western Digital Announces Client NVMe SSDs With New In-House Controllers
Original WD SN520 512GB 256GB 128GB M.2 2242 NVME Internal Solid State Drive Western Digital
CompuCare :: WD PC SN520 256GB NVMe SSD
WD SN520 256 GB NVME ssd | Jawa
Western Digital Announces the PC SN720 and PC SN520 NVMe SSDs | TechPowerUp
WD PC SN520 NVMe 128GB SSD Hard Drive Clear | Techinn
Western Digital, SN520, 256GB, M.2 NVMe, Refurbished – Joy Systems PC
Western Digital SN520 128 GB M.2-2230 PCIe 3.0 X2 NVME Solid State Drive (SDAPTUW-128G) - PCPartPicker
Original WD SN520 512GB 256GB 128GB M.2 2242 NVME Internal Solid State Drive Western Digital M.2 2242 NVME SSD For Laptop - AliExpress