Majacraft Jumbo Wood Bobbins
I have Two Jumbo wood bobbins that sustained some damage. The price of 40 usd is for one, but there are two available.
One of the composite grooves that the tension cord sits in when the wheel is in operation has come off and split. They have come unglued and are no longer able to be tensioned on one side. You can snap the rings back on, but they are starting to split so the one side is not able to be tensioned.
I spun with them and didn't notice any balance issues with them.