Features: Contact us if you have questions,we will try our best to serve for you. Headphones that have been paired can be automatically connected back when they are connected to the transmitter for ns without pairing. Pair the second headphones, turn on the second wireless headphones, press and hold the other button, the light blinks, enter the search, pairing is successful, and the light is on. (Note: when configuring the second headphones, the first headphones will be disconnected and connected automatically after success) Simultaneously press the 2 buttons for 4 seconds to clear paired devices and restore factory settings. brand new and high quality Turn on the wireless headphones to enter pairing mode, insert the bluetooth-compatible transmitter, press and hold the button for 4 seconds, the corresponding led light blinks, enter search mode, pairing is successful, and the light is on. Specifications: Weight: about 20g Chip: csr 2 in 1 Version: 5.0+edr Distance: 10 Meters Working Voltage: usb DC5V Input Interface: TYPE -C Size: about 1.4x4.8x0.5cm/0.55x1.89x0.19 inches Frequency Range: 2.402-2480ghz Support protocol: Aptxll Aptx sbc a2dp afh hsp Package Includes: 1 x Adapter, 1 x Manual. note: Please allow 0-1cm error due to manual measurement. Make sure you do not mind before you bid. Due to the difference between different monitors, the picture may not reflect the actual color of the item. Thank you!