A high quality, low latency, battery powered bluetooth rx/tx device. The one I bought years ago is the Boltune BT-BA001. [0] It is easily my most used inexpensive piece of electronics.
Use cases:
1. Make your stereo system bluetooth, this includes a nice new pair of powered monitors, or a vintage 70's system.
2. You have an older car, want bluetooth but appreciate high quality audio.
3. You want to make your wired headphones wireless.
4. Buy 2, and make a low latency wireless audio link.
These things are super cool, and are now only $30.
Use cases:
1. Make your stereo system bluetooth, this includes a nice new pair of powered monitors, or a vintage 70's system.
2. You have an older car, want bluetooth but appreciate high quality audio.
3. You want to make your wired headphones wireless.
4. Buy 2, and make a low latency wireless audio link.
These things are super cool, and are now only $30.
[0] https://www.ebay.com/p/18030903120