Unique Tube Collet with "thru-hole" design for production tube fly tying! Accepts a variety of metal tubes as well.The Crest # 600 is fully adjustable and has a rotation feature for full visibility of the fly. Comes with our "Lifetime Guarantee". Two different size mandrels and an additional special collet for smaller size tubing and many of the European style tubes. You can also adapt our Standard 3000 vise head for conventional tying.