The Benchmade 591BK Boost is brand new for 2019. The 591 takes the original 590 and improves it in several areas. The blade has been upgraded to CPM-3V and the tip has been blunted so that you actually can finally use your knife as a pry bar....(we know you are going to). The Versaflex handles are improved for grip and better wear. A right or left hand deep carry clip finishes it off nicely.