A perfect example of a well thought out unique design and high level of craftsmanship that fits our "keep it simple" philosophy. No screws or other mechanical locking mechanisms, just a high quality tempered carbon steel needle ground flat on both sides to give locking edges that will keep any Pro Sportfisher tube, or any other tube for that matter in a firm grip, and still be easy to remove when the fly is tied. The Pro tube needles fit all fly tying vices, and this combined with a very low weight is why the Pro Sportfisher tube needles are the reference tool for serious fly tyers across the globe and have been for the past decade.