The knife we like the best we call the "gripper". It has a non-slip surface on the handle, an anti-roll ring (keeps the knife from rolling off the table and trying to stab you) and, best of all, it has extremely tight twist type retraction tightening. The blade doesn't keep working loose at just the wrong time. uses standard blade that fits all hobby knives. Our "gripper" is made specifically for us and it is (you guessed it) green.