Features Long Service Life: The collet extension rod is made of high‑speed steel with stable performance, has strong stability, wear proof, durable to use, which has long service life. Wide Application: Straight shank extension connecting rod, can be used for trimming machine, electric router, engraving machine. Used in various machining applications, including boring, milling, reaming, tapping and grinding. Increase Stability: The extension rod has been accuracy ground to eliminate unbalance and increase stability during cutting. Easy to Use: Fine workmanship, good flexibility, high accuracy, small size for easy installation, is easy to be install, don't need to use much time on installation. Lever Principle: The less the clamping part of the shaft, the greater the force the shaft bears, especially when the cutter head is large. Therefore, make sure that at least 3 / 4 of the handle must be inserted. Specification: Condition: 100% Brand New Item Type: Milling Cutter Extension Rod Material: High Speed Steel Color: Black+Silver Model: Extension Rod 1/2in Shank Application: Can be used for trimming machine, electric router, engraving machine. Package List: 1 x Extension Rod Package List 1 x Extension Rod