Professional electrician installation required; installation fees for Smart Home Panel not included. a Installation-free | Forget expensive and complicated systems, it&&';;s easier than ever to prepare for blackouts with a plug-and-play design. Simply connect to your breaker panel via a power inlet box or transfer switch for instant home backup.a Clean home backup alternative| Exchange noisy, high-maintenance gas generators for quiet and reliable home backup and convenient EV charging.a Power almost everything | Already have two DELTA Pros? Get an extra Double Voltage Hub now and pair two units to hit the massive 7200W and 240V output to power your entire home, including high-wattage ones.a Up to 1 week of power | Expandable capacity from 7.2 to 21.6 kWh with extra batteries, store energy and keep your critical circuits running for up to a week.a Fast recharging between outages | With the signature X-Stream technology, ideal for fast charging between short outages.Note: 1. 1x 1.5m NEMA L14-30P to L14-30R cable is included in this bundle to hook up the Double Voltage Hub into your home&&';;s power inlet box. 2. The Double Voltage Hub requires two EcoFlow DELTA Pro units.