The new MT5 features not only a double-sided flat key but also 3 active locking mechanisms: - The locking bar mechanism is one of the three technologies featured in the MT5 . Correct alignment of the top bar pins depends upon the correct combination key being inserted. - The new -generation product is also based on a new configuration of Mul-t-lock's well-honed telescopic pin technology. - The tip of the key has a revolutionary mobile interacting spring - the Alpha Sprring. The Alpha Spring engages a unique pin at the rear of the mechanism, creating another shearline. All MT5 products have a double-sided unique MT5 key. One set of cuts is for the telescopic pin mechanism and the other cut, the milled pattern, is for the locking bar.