This set of needles from addi is perfect for projects that have a need, a need for speed. The smooth finish, and unique needle to cable connection ensures that the stitches will fly off the needles. The convenient carrying case means that your needle set can travel with you, meaning you'll always have the right size needle for whatever project that you need to cast on. Including needle sizes from US 4 (3.5mm) to US 10 1/2 (6.50mm). Included are several cords and a cord connector for a wide array of lengths. Also included is the key that locks and unlocks the unique click connection that is unique to addi Interchangeable Needles. Please don't hesitate to contact us with any questions.