Back in 2011, Under Armour first announced its Armour E39 shirt, an activewear garment that tracks its wearer’s vital workout stats with a tiny electronic device.

Now, the company has invited customers to pre-order the system, which has dropped the E and become Armour39. The system is comprised of a “module” (the electronic device), chest strap, mobile app and optional display watch. The unisex chest strap, which is adjustable from 27″-52″, can be worn under any workout clothing; you don’t need to purchase a specific Under Armour shirt to use the system.

The module stores your biometric info—including heart rate, calories burned, real-time intensity, and “Willpower” (a 1-10 rating calculated using these biometrics). The data is transmitted automatically via Bluetooth in real-time to the Armour39 App (coming soon) or Watch (sold separately). The module stores up to 16 hours of workout information, and transmits within 15 feet of your Bluetooth-enabled mobile device. With the app’s calendar, athletes can compare daily workouts and track improvements and trends over time.

You won’t need to charge the module, which runs on a standard CR 2032 3V watch battery that lasts up to 9 months (remove the module from the chest strap after your workout to preserve battery life).

The Armour39 module and chest strap will run you $149.99; the watch is $199.99. Both will be available in “Spring 2013.”

Amanda Pendolino

Amanda has been writing for several entertainment, tech, shopping and business websites since 2009. A resident of Los Angeles, she also works as a screenwriter, script reader and tutor. She's obsessed with film and TV, and is not afraid to admit that her Samsung Galaxy SIII is her most prized possession.