The Serum folders are brand new Benchmade knives and the first to use the AXIS Dual Action mechanism. If functions exactly the same as a regular AXIS lock but allows for both manual or automatic action, depending on your mood. To get the lighting fast AUTO action, pull back on the AXIS lock, then pull back a little further and smack! The blade opens ultra-smoothly when using the thumb studs and fast and hard when using the AUTO mechanism. The G10 handles, 154CM stainless steel and reversible tip-up carry pocket clip make this a great knife for anyone. This is definitely a Benchmade series you have to check out and you can find them at www.knifecenter.com.