Replacement battery for Philips HeartStart FR2 and FR2+ AED defibrillators — 12V 4.2Ah Li‑MnO₂ (50.4Wh), non‑rechargeable, direct replacement for OEM M3863A, also compatible with M3840A/M3841A. Up to 4‑5 years standby life ensures defibrillator readiness for cardiac arrest response. CE, RoHS, UN38.3 certified.
