Addi Click Interchangeable Knitting Needles require no tools to change; simply insert the cord into the tip, twist and release. The tips will remain secure until you change them, thanks to the Click’s revolutionary locking mechanism. You may combine any set of tips with any cord length to get exactly the combination you need. The possibilities are almost endless, with more than five-hundred tip, cord, and connector combinations across the full spectrum of needle sizes and cord lengths. All Addi products come with the standard Addi lifetime guarantee.