As one of its daily deals, A4C offers the used Fitbit Charge 2 HR Wireless Activity Wristband in Large or Small for $39.95 with free shipping. That's tied with our mention from last December, $60 below the lowest price we could find for a new one today, and the best deal we've seen for this tracker in any condition. Deal ends today. It tracks steps, distance, sleep, and calories and features an OLED display with clock, continuous heart rate monitoring, multi-sport modes, Bluetooth 4.0, smartphone notifications, wireless sync with supported computers and smartphones, and a battery life of up to five days.