Tao has apparently been around the business of small electronics for quite a while and I can say that 1000% they know what they're doing when they make their transmitters, receivers, and their 2-in-1 TX/RX!***Fyi***If you have hard-wired, non bluetooth capable headphones like myself and plan on using those headphones via bluetooth but want to connect them to a hard-wired home theater system, you will need (2

Then put the other (#2) in RX mode, connect it to your hard-wired, non-bluetooth headphones, and turn on

So tiny you'll forget it's plugged into your personal, hard-wired, non-bluetooth capable headphones

So these IEM's are not bluetooth ready/capable right out of the box... rather at all, because to get the insanely good sound quality out of these IEM's, you have to have it hard-wired to the "tuner box" artists wear or hard-wired to a DAC headphone amp