Apple watch series 1 42mm gold aluminium case with midnight blue sport band type smartwatch smart compatibility iphone connectivity bluetooth power rechargeable lithium ion battery up to 18 hours of battery life 1 view iphone messages calendar reminders app notifications answer or dismiss incoming calls health fitness tracking with heart rate sensor 2 watchos 3 s1p dual core processor ion x glass oled retina display with force touch 312 x 390p