Danica Danvise Innovation Cam Fly Tying Vise. The Danvise fly tying cam vise has jaws that swivel on two ball bearings, thereby binding the materials around the hook when it rotates. It is a new principle that makes it easier and faster to tie professional looking flies. The Danvise can naturally be used for traditional tasks also. The vise jaws hold hooks of all sizes completely immoveable. the jaws are opened and closed using a cam-arm. It does not get any easier or better. The Jaws are made of top quality, perfectly tempered steel.