Apple Watch Series 4 (GPS+LTE) 40mm Silver Aluminum Case Seashell Sport Loop (Used)

The Apple Watch Series 4 (2018) was a major redesign, introducing larger edge-to-edge displays (40mm & 44mm), faster S4 chip, louder speaker, and groundbreaking health features like an electrical heart sensor for ECGs and advanced fall detection, plus improved GPS, cellular options, and watchOS 5, making it a significant step in fitness tracking and communication.