Caution Suitable for all Bluetooth headsets Not!

The transmitter is quite small, well made and works flawlessly, just in absolute silence you can hear a faint noise!
Caution for those who want to use the device in conjunction with a Bluetooth Headset / Headphones!
It does not detect all Bluetooth headsets I have tested it on two:

- ARCTIC P253 Bluetooth Headset (BT version 3.0) with pairing code (0000,1234,1111,8888, etc.)
- August EP650 Bluetooth Wireless Headphones (BT version 4.0) Code Free

The device actually recognizes only the Bluetooth devices that have one of these gängingen PIN code.
Devices with different or no codes can not connect. The transmitter then proceeds in the Pairung mode,
flashes very wild and then go out or to standby mode.

Perhaps this information is kaufentscheidend..zumindest for some, it would have been helpful for me!
I also have a weitreres device tested (CSL Bluetooth dongle / transmitter). Here it is the same problem!