G-Shock GBA900UU-5A Tan One Size

Product Overview

The G-Shock GBA900UU-5A from Casio brings the trusted toughness of the G-Shock line into the urban fitness arena. Part of the G-SQUAD series, this watch is built for those who move—whether that’s through city streets, gym floors, or outdoor trails. With its understated tan colorway and compact resin design, the GBA900UU-5A offers a balanced blend of athletic function and everyday style. It’s engineered not just to withstand impact and weather, but to actively support an active routine through smart tracking and intuitive timekeeping. Lightweight at just 61 grams and measuring 51.3 × 48.9 × 16.6 mm, it sits comfortably on the wrist without sacrificing presence or durability. Whether you’re logging steps, timing intervals, or switching between time zones, this watch delivers consistent performance in a form that fits seamlessly into daily life.

Key Features

• Bluetooth Mobile Link – Automatically pairs with your smartphone using Bluetooth® technology, enabling wireless synchronization with the Casio Connected app. This allows for effortless updates to world time settings, alarm configurations, and activity tracking data—eliminating the need for manual adjustments and keeping your watch current wherever you go.
• Lifelog Fitness Tracking – Tracks daily movement by calculating calories burned and distance traveled based on step count. The system incorporates basal metabolic rate (BMR) to deliver more personalized energy expenditure estimates. Daily summaries—including total steps, estimated calories, and distance—are clearly accessible on the digital display, helping users monitor progress over time.
• Dual Time Function – Features a home city time swap that lets you instantly toggle between your local time and a second time zone. This is especially useful for travelers, remote workers, or anyone coordinating across regions, ensuring you stay on schedule without confusion.
• Precision Stopwatch & Timers – Equipped with a 1/100-second stopwatch for split timing and a countdown timer for interval training or timed tasks. These tools support detailed workout tracking, whether you’re timing laps, managing rest periods, or measuring performance.
• 5 Daily Alarms & Hourly Signal – Set up to five daily alarms to manage routines, reminders, or training schedules. The hourly time signal provides consistent time checks throughout the day, helping maintain structure and punctuality.
• Double LED Light – Illuminates both the analog hands and digital display with even, bright light, ensuring full visibility in dark environments or low-light conditions. The dual lighting system enhances readability without straining the eyes.
• Shock & Water Resistance – Built with G-Shock’s signature shock-resistant structure to absorb impacts from drops or bumps. Combined with 200-meter water resistance, it’s suitable for swimming, snorkeling, and other water-based activities, as well as rugged outdoor use.
• Hand Shift Feature – Temporarily shifts the analog hands aside to provide a clear, unobstructed view of the digital screen. This is especially helpful when checking fitness data or settings without interference from the watch hands.
• Power-Saving Design – Includes a power-saving mode that conserves energy when the watch is not in use, along with a low battery alert to notify you before power runs out. Powered by a CR2025 battery, it delivers approximately two years of operation under normal use.
• Airplane Mode – Disables all wireless communication functions, including Bluetooth, to comply with airline regulations during flights. Easily reactivated once you land, restoring full connectivity.

Technical Specifications

• Case Dimensions: 51.3 × 48.9 × 16.6 mm
• Weight: 61 grams
• Case & Bezel Material: Resin
• Band Material: Resin
• Glass Type: Mineral Glass
• Water Resistance: 200 meters
• Battery Life: Approximately 2 years (CR2025)
• Timekeeping Features: Hour, minute, second, AM/PM, month, date, day
• Calendar: Full auto-calendar (programmed to year 2099)
• Time Format: 12/24-hour selectable

Benefits & Use Cases

The GBA900UU-5A is designed for individuals who value both function and resilience. Fitness enthusiasts benefit from real-time tracking of steps, calories, and distance, while the inclusion of basal metabolic rate in calculations offers a more accurate picture of daily energy use. Commuters and travelers appreciate the dual time function, which simplifies managing schedules across time zones. The watch’s 200-meter water resistance and shock-resistant build make it reliable during swimming, hiking, or high-impact workouts. Bluetooth connectivity enhances usability by syncing data with the Casio Connected app, allowing users to review trends and adjust settings from their phone. Despite its advanced features, the watch remains lightweight and comfortable for all-day wear, whether you’re in a meeting, at the gym, or exploring nature. The tan resin band and case offer a neutral, modern look that pairs well with casual and athletic attire.

Important Notes

Battery life is an estimate and may vary depending on usage patterns, particularly with frequent use of Bluetooth, alarms, or the LED light. The Lifelog function is intended for general fitness monitoring and is not a substitute for medical-grade devices. To maintain water resistance, ensure the battery compartment is securely closed after any maintenance. The watch includes a standard manufacturer warranty; refer to Casio’s official documentation for care instructions and warranty details. Model number: GBA900UU-5A.