The hardened steel jaws of the Terra Rotating Spring Action Vise can be rotated 360 degrees for winding materials and viewing. The jaws easily open and close by simply squeezing a lever for hook release. This vise is a great choice for anyone tying a lot of large flies such as bass flies or saltwater flies since it firmly holds hooks as large as 4/0 while still working great with hooks as small as size 20.