My wife has wanted for along time to use various 25mm knitting needles for her large yarn projects, so this kit was designed to fulfill her many requirements in a very flexible way. This 25mm knitting needle kit allows many configurations, including standard needle, circular needles, both double and single ended, and broomstick lace needle. The individual segments are attached using either a male or female thread, plus a grub-screw for changing the female into a male screw. Each of the parts was printed in white PLA. I needed to under-extrude when printing (92%) to ensure there were no surface blobs that might catch on the yarn. The very tip of the needle was gently sanded to remove a tiny string of plastic and to make it perfectly smooth. Anything other than perfectly smooth will catch on the yarn and make knitting or crocheting difficult. Each segment can be mixed and matched depending on the required configuration, but to actually purchase all of those needle types in 25mm thickness individually would cost more than $50. The circular needle and broomstick lace configuration requires a short length of 5mm aquarium tubing to join the ends. Just push the tube into the pieces called base or base-A and tie a knot to stop it from slipping out. To test out the needle, my wife downloaded this free broomstick lace pattern by Vita Apala: http://monpetitviolon.com/2014/11/11/free-pattern-broomstick-lace-cowl/ She used a multi hued red yarn to make the final cowl, and she gave the cowl to a friend as a birthday present.