ZGRAV FLIPPERS ZGrav flipper utilize sealed stainless steel bearing to allow for minimal drag on the blade during the opening process. This permits user to snap open the blade without a wrist flip. Zgrav knives open as quick as switchblade's without needing springs. As Zgrav's cannot be opened by centrifugal force they do fall into the definition of a gravity knife. Check out the YouTube link to see ZGrav's in action.Knives can be made Lefty or Righty.