Description
EG4 FlexBOSS21 — 16kW Split-Phase All-in-One Hybrid Inverter | NEMA 4X | 21kW Solar Input | EMP Hardened
The EG4 FlexBOSS21 is the most capable inverter in EG4’s FlexBOSS lineup — a 16kW split-phase hybrid inverter/charger built for large homes, demanding off-grid properties, and installations where maximum output, extreme load-start capability, and long-term environmental durability are non-negotiable. With 21,000W of solar input across three MPPT channels and five string inputs, 16,000W of continuous AC output when solar is present, a 156A locked-rotor amperage rating that can start a 5-ton air conditioner, a NEMA 4X coastal-rated enclosure, EMP hardening, and purpose-built integration with the EG4 GridBOSS MID — the FlexBOSS21 delivers a feature stack that stands alone in its class.









Caleb (verified owner) –
Professional and trustworthy seller.
Mark (verified owner) –
The quality is outstanding.
John (verified owner) –
Everything arrived in excellent shape.
Stephen (verified owner) –
No issues at all, great experience.
Leah (verified owner) –
Everything went exactly as expected.
Dennis (verified owner) –
Five stars for quality and service.