Casio WU-BT10 Bluetooth Wireless Adapter - Open Box
Casio WU-BT10 Wireless Bluetooth MIDI/Audio Adapter for CT-S400, CT-S1 and LK-S450 | Sweetwater
Amazon.com: Casio Wireless Bluetooth MIDI/Audio Adapter (WU-BT10) : Everything Else
PKPOWER Cable 3.5mm Audio In Cable AUX In Cord For Casio CTK-2300 61-Key Portable Arranger Digital Electric Piano Keyboard (6 Feet 1/8 Stereo Audio Input Lets You Hook Up Your Music Player -