Grissom Knife and Tool Prototype Tanto Recurve ring dagger. This knife is a prototype and was obtained directly from Grissom at the Blade show in 2019. The knife has a unique recurve tanto shape blade 2 3/4″ long of AEB-L, 1/8″ thick, 7 1/4″overall length. This knife come in a carbon fiber kydex sheath with a ulticlip. The knife feels very good in the hand, has OD G-10 grips with “13” engraved in them.