[What's It Used For] - Used to connect 1 set of BLUETTI AC500&B300S power station with the main panel to build up a home backup system in rated capacity/voltage/power up to 6144Wh / 120V / 5000W. [24/7 UPS Home Backup] - Tie the AC500&B300S power system to your home grid to power your home whenever a blackout occurs. Only a licensed electrician can install the UPS power system. [Compatible Version] - It only works with 100-120V US plug version. [What You Get] - 1 × 50A outlet box (Reliance), 1 × sub-panel (Included a 50A inlet SS2-50), 1 × 50A AC charging cable for AC500, 1 × NEMA14-50 to SS2-50R cable. BLUETTI Home Integration Kit by Reliance to Connect the AC500 Power System to the Home Main Panel