The cross key device from KnitPro is a truly functional device that helps you wind up yarn from fat to yarn key, which is what you knit from. A cross wrench device saves you a lot of time compared to winding the yarn by hand.

The cross wrench device is easily mounted to a table top when you need to use it, and is easy to pack away afterwards. With the wound yarn key from the cross key device, you can knit both from the outside and the middle of the key.

See also the wooden twine winder here to complete the set.