For Samsung Galaxy Watch3 45mm (R840) - Replacement Rear Housing Shell Assembly - Mystic Black

Restore the structural integrity and biometric precision of your wearable with this Replacement Rear Housing. Specifically engineered for the SM-R840 stainless steel architecture, this Mystic Black shell is manufactured to original factory tolerances to ensure an airtight fit with the internal electronics. It is the definitive hardware solution for resolving cracked rear glass, compromised heart-rate sensor windows, or moisture ingress caused by chassis damage. This assembly maintains the precise alignment required for consistent PPG sensor contact, ensuring your health monitoring and wireless charging remain reliable for peak daily performance.