The NES and SNES Classic systems support SD cards : r/miniSNESmods
GUIDE] How to add games to your fake/clone SNES Classic | GBAtemp.net - The Independent Video Game Community
Internal Micro SD Board of SNES MINI Console - J&T Studio
The Nintendo classic (not so) mini thread - Bordersdown (NTSC-uk)
Tutorial SNES Mini SD Card Mod - YouTube
SNES Classic Hardware - XOR
Samrad China Version SD2SNES Revision F SNES SD2 Por Retro Game Card Super Alpha 16-Bit Video Game Card For US Game Console : Amazon.co.uk: PC & Video Games
SNES Classic Mini Internal Bluetooth Modification : 6 Steps (with Pictures) - Instructables
SNES Classic: *External* MicroSD, DC Input : r/miniSNESmods
SD2SNES Review – VideoGamePerfection.com
Snes Mini Sd Card - Accessories - AliExpress
Tutorial SNES Mini SD Card Mod - YouTube
Nintendo Classic Mini SD Card Mod - MrJSA Technologies
Sd Snes - Etsy UK
RGB PCB Mod SNES Amp with CSync (THS7374) Kit For 1 CHIP-03 and SNES Mini/SFC Jr | eBay
Memory Stick Micro SD Adapter for PSP | Hand Held Legend
SNES Super Nintendo Mod with SD Card Adapter UK | Ubuy
SNES Classic Hardware - XOR
By far the cheapest Micro SD method : r/miniSNESmods
SNES Mini review - "Has lightning struck twice for Nintendo?" | Pocket Gamer