These flexible rubber hollow cords from Minnie & Purl are perfect for trying on your knitting without removing any of it from your needles!
The end of the cord squishes firmly over most size needles. After it is attached to your needle tip, simply slide stitches on to the flexible tubing so you can try your sweater on. When you are done, push all of the stitches back onto the needle and pull off the tubing.
Each pack comes with 3 cords (two in ~1.09 yard/1 meter length, and one in ~2.75yards/2.5 meters length) all in a secure screw top circular tin.