Siemens 5SL4563-7 SENTRON MCB — 63 A, C-Curve, 1P+N
At 40 °C ambient the continuous rating derates to 59.67 A; at 55 °C it drops to 54.29 A — factor that into the branch-circuit load calculation if the panel runs warm. The neutral pole switches with the line (1P+N, not 2P), so the neutral is opened and closed together with the phase. That matters for isolation — you get full disconnection on both conductors, not just the phase.
Mounting position is unrestricted, so it can be installed horizontally or vertically without derating the current. For frequent switching as a load-break device, consider a contactor instead.