Apple Watch Ultra 4 GPS + Cellular 49mm Natural Titanium Case with Sand Trail Loop Band - MJAJ4LS

Key Features

Design & Durability

• Aerospace-grade titanium case: Available in Natural and Black finishes; 49mm size with 100m water resistance and IP6X dust resistance

• Sapphire crystal display: Flat sapphire crystal with 3,000 nits peak brightness and 1 nit minimum for Night Mode

• Sand Trail Loop: Lightweight polyester weave band with titanium G-hook for a secure, adjustable fit

Health Sensing System

• Most accurate heart rate sensing in a wearable: Redesigned optical and electrical heart sensors validated by a study of over 1,000 participants

• Continuous background monitoring: Measures heart rate every 5 seconds throughout the day for deeper fitness and physiological insights

• HRV measurement up to 24x more frequent: Provides both Recovery HRV and Overall HRV for daily stress/recovery signals and broader cardiovascular health

• Readiness Score: Daily score (0–10) analyzing recent activity, Training Load, vitals, and Sleep Score with actionable recommendations

Performance & Battery

• S11 chip: 64-bit dual-core processor with 4-core Neural Engine and 64GB storage, enabling advanced on-device processing

• Up to 50 hours battery: More than two days of battery life in normal use

• Up to 84 hours in Low Power Mode: Extended battery for longer adventures

• Fast charging: 15 minutes of charge provides up to 18 hours of additional battery life

• Max Extended Workout mode: Up to 45 hours of outdoor workout tracking

Safety & Connectivity

• Satellite communications: Emergency SOS, Find My, and Messages via satellite included free for two years with activation

• Precision dual-frequency GPS (L1+L5): Most accurate GPS in a sports watch

• GPS + Cellular (5G): Stay connected without iPhone nearby

Intelligence & watchOS 27 Features

• Siri AI with Apple Intelligence: Personal context understanding and broad world knowledge on the wrist

• Audio Intelligence: Includes Live Rewind, Siri Recap, Sound Recognition, and faster Shazam

• New single-handed tap gesture: Open Smart Stack widgets by tapping index finger and thumb; double tap to scroll, single tap to select

• Cycle Tracking support: Now includes perimenopause and menopause support

• Workout Buddy: Available on Apple Watch without iPhone nearby, with expanded fitness data

Environment

• 45% recycled material overall: Includes 100% recycled titanium in the 3D-printed case and 100% recycled cobalt in the battery

• 100% fiber-based packaging: Recyclable at home

Compatibility

• Requires iPhone 11 or later with iOS 27 or later

Note: The S/M Trail Loop fits wrists measuring 130–180mm. A separate M/L size (MJAQ4) is available for wrists measuring 145–220mm .