Mini Bluetooth 5.1 Audio Adapter - With upgraded version of Bluetooth 5.1 technology, enjoy non-inductive delay to improve call sensitivity and connection stability. You just need to connect it with Non-Bluetooth devices, then they can be upgraded to Bluetooth devices, and the in-ear earphones can effectively isolate noise and enjoy music easily. Wide Compatibility - Audio receiver for headphones, home/car stereo. Works with most devices like Phone, Tablet, laptop, most speakers, etc. The standard 3.5mm audio adapter is suitable for any powered PC speakers, car/home stereo sound system and wired headphones. Safe Hands-free Calling - Provides you with the safety and convenience of hands-free calling while driving. The adapter equipped with noise cancellation technology, suppress environmental noise, pick up human voices more accurately, and easily listen to the sound quality of CD records. Upgrade Two Modes - Freely switch between Bluetooth/TF card modes, support WAV/FLAC/APE lossless format playback. Super-capacity lithium battery, listening to music for about 20 hours, easily meet all-weather and daily commuting entertainment needs, LED real-time power display, power consumption at a glance. Spring Back Clip Design - It is firm and does not fall. Light weight with wearable clip, specially designed for sports and music lovers, just hang it on your pocket or jacket to enjoy music while running, jogging, hiking or doing other exercises. Color: Black Material: plastic Package Contents: 2 x Bluetooth Receiver Only the above package content, other products are not included. Note: Light reflection and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.