I arrive home from work excitedly anticipating the 561, my first flipper. I hurry the the mailbox, rush into my kitchen to open the package, and open the box. I tear out the knife as fast as I can ignoring my crying cat's pleas for food or whatever, I quickly admire the knife closed, now it's time to flip. I don't know what I was thinking I just wanted to flip the blade open and fully admire the knife, I proceed to place my index finger on the flipper and I flip the blade right out of my hand and I just stare at it while it's spinning as it crashes to the floor. Oh no, I've damage the knife and I haven't even had it for 30 seconds. I collect myself and pick it up to carefully inspect the edge, blade, handle etc. Not a single scratch or scuff. Time to try this again. I attempt to close the blade by using my index finger pushing on the flipper and get bitten like an idiot. I thought I'd be faster than the knife but the 561 proved my wrong twice in less than a minute. Anyways, I really like the knife's size, it's perfect for me. It's lighter than expected, but no less sturdy. The action is fast and locks solid like a vault, entirely free of any blade play. The 561 will become my casual edc, while the 550 will be my work knife.