Always know, in a glance, exactly how many rounds left. The innovative & exclusive counting magazine has a color & numeric indicators on the rear & bottom of the magazine. According to the left rounds in the magazine – numbers appears on three different backgrounds: 30-21 green, 20-11 rounds yellow, 10-0 rounds red. The rear indicator is colored & numeric – allows the exact information without losing eye contact from target or loosing the body position. The bottom indicator is colored & has a numeric additional spare indication – allows the information, so you know what magazine to use next from the vest pouch. Countdown Magazine For 5.56mm 100% reliable – non-tilting & a corrosion resistant stainless steel spring. Mechanism does not interfere disassembly. Proven in extreme conditions, such as rapid fire & water. Fits the MCD16 – our magazine coupler.