What is the difference between the Nrf_4Mbit_0BT6 and Nrf_4Mbit_0BT4 in nRF54L15 RADIO MODE?

[LeeRJ]

What is the difference between the Nrf_4Mbit_0BT6 and Nrf_4Mbit_0BT4 in nRF54L15 RADIO MODE