At a church sale my eyes locked on a pair of silvery blue metallic knitting needles with green plastic points and flat gray ends. They are big, 3/4 inch in diameter. Now how I managed to measure the diameter with such accuracy and express with such certainty is that I discovered, when I got them home, that the gray ends are removable, and the needles hollow. Why? I Googled but that only got me some places on e-bay selling them. Those hollow rolling pins which you can fill with water and put in the frig to chill which apparently makes rolling out dough easier came to mind and I wondered if these knitting needles are meant to be filled with water. Cold water for knitting when it is hot? Warm water for knitting when it is cold? Sand for increased weight and increased exercise when knitting? A place to stash smaller needles? I think the noise of these rattling around inside would be annoying. Candies? Ditto. I can’t think of anything obvious. ??? I need to ‘travel’ a bit with these jumbo jets………