Introduction
This manual provides detailed instructions for the operation and maintenance of your Timex Ironman Triathlon Classic 100 watch. Designed for athletes and active individuals, this watch features a 100-hour chronograph, 100-lap memory, interval timers, multiple alarms, and water resistance up to 100 meters. Please read this guide thoroughly to ensure proper use and to maximize the lifespan of your watch.

Front view of the Timex Ironman Triathlon Classic 100 watch, displaying the digital screen and button layout.
Official product video showcasing the Timex Men's TW5M03400 Ironman Classic 100 watch and its features.
Official video from Timex Corporation highlighting the Ironman Classic series.
Getting Started: Initial Setup
Setting Time and Date
- Press and hold the SET/RECALL button (top left) until the time display flashes.
- Press the MODE button (bottom left) to cycle through hours, minutes, seconds, year, month, and day settings.
- Use the START/SPLIT button (bottom right) to increase the flashing value, or the STOP/RESET button (top right) to decrease it.
- Once all values are set, press SET/RECALL again to exit the setting mode.
Activating INDIGLO Night-Light (FLIX Technology)
The INDIGLO night-light uniformly illuminates the watch dial. For hands-free illumination, activate FLIX technology:
- Press and hold the INDIGLO button (top right) for three seconds until it beeps to activate Night-Mode.
- Once Night-Mode is active, a firm forward flick of your wrist with a sharp stop will illuminate the night-light for 5 seconds. This requires a deliberate motion to prevent accidental activation.

Side view of the watch, highlighting the function buttons for setting and operation.
Operating Features
Chronograph (Stopwatch)
The 100-hour chronograph with 100-lap memory is ideal for tracking workouts. It features a 199 lap counter and on-the-fly recall of lap or split times.
- Press MODE to navigate to Chronograph mode.
- Press START/SPLIT to begin timing.
- Press START/SPLIT again to record a lap or split time.
- Press STOP/RESET to pause the chronograph. Press again to reset.
- Use RECALL to view stored lap and split times.
Interval Training Timer
Set up to 9 interval timers, each settable up to 24 hours, with options for countdown/stop or countdown/repeat. This is useful for structured workouts.
Alarms
The watch includes 5 customizable alarms. Each alarm can be set for a specific time and day pattern (e.g., daily, weekdays, weekends).
Dual Time Zones
The watch supports two time zones, allowing you to easily switch between them, which is convenient for travel.
Maintenance
Battery Replacement
The watch uses one Lithium Metal battery (CR2025). When the battery needs replacement, it is recommended to have it done by a qualified watch technician to ensure the water resistance seal is properly re-inserted. Improper battery replacement can compromise the watch's water resistance.
Water Resistance Guidelines
Your watch is water-resistant to 100 meters (330 feet). This makes it suitable for snorkeling, swimming, and showering. However, it is not recommended for scuba diving. Avoid pressing buttons underwater to prevent water ingress.

Close-up of the watch band and buckle, showing the durable resin material.
Troubleshooting
- Display is blank or dim: The battery may be low or depleted. Replace the battery.
- Buttons are unresponsive: Ensure the watch is not in a locked mode. If the issue persists, a reset may be required (refer to the full user guide for specific reset procedures, if available).
- Water inside the watch: If water appears inside the watch after a battery change, the water resistance seal may not have been properly re-seated. Seek professional repair immediately to prevent further damage.
- INDIGLO light not working: Check if Night-Mode is activated. If not, press and hold the INDIGLO button for 3 seconds. If it still doesn't work, the battery may be too low to power the light effectively.
Specifications
| Feature | Detail |
|---|---|
| Model Number | TW5M03400 |
| Case Diameter | 44 mm |
| Case Material | Resin |
| Band Material | Resin |
| Band Width | 18 mm |
| Water Resistance Depth | 100 Meters (330 Feet) |
| Display Type | Digital |
| Movement Type | Quartz |
| Battery Type | Lithium Metal (CR2025) |
| Special Features | 100-hour Chronograph, 100-lap Memory, Interval Timer, 5 Alarms, INDIGLO Night-Light, 2 Time Zones |
Warranty and Support
Your Timex watch is covered by a manufacturer's warranty. For specific warranty details, service, or support, please refer to the warranty card included with your purchase or visit the official Timex website. Keep your proof of purchase for warranty claims.
For additional assistance, you may contact Timex customer service directly. Contact information can typically be found on the Timex website or in the packaging materials.