5.50mm - Knitpro Cubics Interchangeable Needle TipsFor use in combination with the KnitPro Interchangeable cable range. These represent excellent value for money as once you've bought the KnitPro cable(s) of your choice, you can change the needle tips for each project. Knitpro Cubic needles are recommended for knitters that have arthritis problems, as they are much more ergonomic. The cuboid shape provides comfort to the hand and gives uniform stitch formation. The needle size is measured diagonally