Bluetooth Adapter and Amplifier for Audio Technica ATH-M40x - BAL-M40X - Walmart.com
Deco Gear Wireless Bluetooth Adapter & Amplifier Compatible with Audio Technica ATH-M50X Professional Studio Monitor Headphones - Custom Flush Fit Design , Integrated Control Buttons and Built-in Amp - Walmart.com
Audio-Technica ATH-M50x Professional Studio Monitor Headphones with Bluetooth Adapter-Amplifier BAL-M50X (eb0fec50820ccec9b6f41d5fd2376b4e) - PCPartPicker
Bluetooth Adapter Audio Technica M50x | Bluetooth Adapter Ath M40x - 5.0 Adapter - Aliexpress
Amazon.com: East Brooklyn Labs BAL-Pro50x Bluetooth Adapter for Audio-Technica ATH M50x (Bluetooth Adaptor) : Electronics
Amazon.com: East Brooklyn Labs BAL-Pro50x Bluetooth Wireless Adapter for Audio-Technica ATH M50x Headphones (Pro Gaming Adaptor w/Mic) : Electronics