[BB_TX]

If you are replacing the breaker on the left, the small black wire and small red wire already have in-line fuses in those wires (the black thing behind the red wire at top of pic and the red one near the bottom of the picture). Those wires are effectively wired direct to the battery (since the are connected to the line side of the breaker) and are already fuse protected. So put the wires on the new breaker just as they are on the old one.