Circular needles allow you to knit "tube" projects in the round such as socks, cowls, hats - anything you fancy really! The best part is they can be used for flat knitting too - at the end of each row, just switch the needles around as you would with normal single-points, meaning your project sits in your lap as you work, instead of weighing down your poor arms! Interchangeable needles give you even more flexibility - just screw the cable into the needle tip and tighten with the key provided. The folk at Knit Pro are so clever they"ve even thought to provide cable "caps" as well, to hold your stitches on the cord when you want to use the needle tips for another project.Interchangeable needles give you even more flexibility - just screw the cable into the needle tip and tighten with the key provided. The folk at Knit Pro are so clever they"ve even thought to provide cable "caps" as well, to hold your stitches on the cord when you want to use the needle tips for another project.This 35cm cable makes a 60cm needle including tips.