We recommend that you flash the latest firmware to get the latest features and bug fixes.

The Bear frame is compatible with stock Prusa firmware, if you use an Original Prusa extruder. If you are using an alternative extruder you might need a different firmware:

Original Prusa extruder: you can use the original Prusa firmware available here.

BearExxa needs a custom firmware for calibration: read the guide here.

BearMera can use the Original Prusa firmware (or Bear calibration firmware) with some restrictions: read more in details here.

Bondtech extruder on stock X axis or Bear X axis needs a custom firmware: you can download it here.

If you don't know how to flash the firmware to your original Prusa, check this guide: https://help.prusa3d.com/en/guide/upgrad...