CobraTec Knives CTTHRBLK: The CobraTec Trapper Hidden Release automatic handle is comprised of textured bone with steel bolsters and comes with a drop point D2 steel blade. Push the bolster up to deploy the blade and push the bolster up again to release the lock. The Trapper has been around for many years and CobraTec is excited to add a bit of modern to this knife by making a hidden release auto.