I bought the BLK-MD-SPK-B for the possibility to change the device name with an AT-command. But when I got it hooked up UART it turned out that the change name command did not work. Bad luck.
The way to change the name was to burn it in to the configuration in the EEPROM-chip:
First you must solder the tiny chip off the board, use tweezers to lift it from the board when you warm up pins.
Hook the chip up to an EEPROM programmer.
Read the data from the chip and save a backup to a file. Then locate the device name.
Replace the old name (in my case “BT-Speaker”) with the name you want for the device (I renamed mine to “Marsboer”) and then write it to the chip.