The Twist screws are high grade carbon steel hex screws with a carbide insert and a specially designed thread. They are zinc electro plated to extend product life with an anti-corrosive layer to stop oxidation. While these screws offer extra strength, they can also be removed. The carbide tip increases traction on many surfaces: snow, ice, mud, slippery rocks, wood, hard packed dirt and gravel, and hills. They also provide added traction for rounding corners and for surprises under the water. Woody’s Twist Screw Line is packaged in a clearly marked, sturdy plastic container for easy shipping and display. Twist screws require a specific tool for installation and removal. Installation tools are available through Woody’s.