7SR5111-1AA21-0AA0Brand: SiemensMPN: 7SR5111-1AA21-0AA0Directional time-overcurrent protection 7SR51 4 curr. trans., 4 volt. trans., 9 BI, 8 BO Standard interface: 1 x USB (front), RS 485 (rear) + 2 x optical LC intRequest a quote