All the rest of the Griptilian hardware—the blade, Axis-Lock, pivot mechanism, and so on—remains the same. The upgrade is available for Benchmade’s model 550, 550HG, 551 and 552 without any modifi cation to the original knife (they will not fit the model 553 with tanto-shaped … The upgrade consists of replacement scales and a back spacer, and he calls the finished product Griptilikins.