The whip finish is the perfect knot to tie off your fishing flies with. These Dr. Slick whip finishers make tying a whip finish a breeze. The standard size works on all sizes of flies when tying off the head. Use the extended reach whip finisher when you want to reach farther back on the hook shank to tie off. We use an extended reach on our bass bugs where we are tying off each step of the fly. This is a must have in your fly tying tools.