Under Amour offers its Under Amour Armour39 Performance Monitor in Black for $99.99. Coupon code "MMFSAVE70" drops it to $29.99. With free shipping, that's tied with our mention from two weeks ago and the lowest total in-stock price we could find now by $45. The included chest strap fits chest sizes from 27" to 52". The module tracks your heart rate, calories burned, real-time intensity, and connects to your iOS or Android phones via several app options.