PS2 Controller Bluetooth Adapter for Android & iOS for PlayStation 2
AKNES 8Bitdo Pro 2 Wireless Bluetooth Controller for Switch/Switch OLED, Bluetooth Gamepads Controller for Steam, PC, Android & Raspberry Pi,with 2pcs Silicone Thumb Grip Caps(Clear Purple Edition) : Amazon.co.uk: PC & Video
Defender - Black (Next-Gen PS1, PS2, PS3, PS Classic, Switch & PC Wire – Games Connection
Interfacing Wireless PS2 Controller with Arduino - YouTube
MayFlash PS2 Controller Bluetooth Adapter for Andriod/iOS/PC (AD001) – SupremeGameGear
Wireless Controller for PS2 Dual Shock, Gamepad Remote Compatible with Playstation 2 (Clear Blue) : Amazon.co.uk: PC & Video Games
Wired Clear Game Gaming Controller For Playstation 2 Ps2 | Fruugo UK
Bluetooth Video Game Controllers for Sony PlayStation 2 for sale | eBay
Blueretro Bluetooth-compatible Wireless Controller Adapter for PS1/PS2 (Black) U | eBay
AUFGLO Classic Wireless Controller for Ps2/Dual Shock 2/Playstation 2/Pc (ClearRed and ClearBlue) : Amazon.co.uk: PC & Video Games
After 5 different bluetooth adapters, I finally found one that lets me use two controllers at the same time with pademu! - Link included : r/ps2
Bluetooth PS2 Controller : 10 Steps (with Pictures) - Instructables