Dreamz needles are made of polished birch wood & will work effortlessly with every type of yarn without interfering with knitting rhythm . The short, interchangeable tips are perfect for attaching to shorter cords to create a 16" circular for making hats. The threaded, screw like system with tightening key will ensure that the needles never come loose when you are knitting. They are lightweight, strong, durable & the smooth join ensures easy stitch glide with no snagging. In addition, the flexible cords will not kink or twist. Each size needle comes in a unique color for easy identification .