Firmware is meticulously tailored to a receiver's make, model, and hardware version ( H/W ). Installing the wrong version, even with a similar-looking name, can permanently damage ("brick") the device.
Because r12943mj2r5370 is not a standard commercial model name (like "Galaxy Watch" or "AirPods"), it typically appears on the "About Device" screen of generic or white-label electronics manufactured in Shenzhen. r12943mj2r5370 software download 2022 link