I have a couple of these left from a tournament they are clear plastic tube holds up to 8 pieces of chalk when fully extended or fits 5 pices or less when fully closed.
shipped without chalk $8.00
shipped with 5 pieces of masters chalk $10.00
They were made just for the chalk, I thought they were pretty cool
Those are really cool. Was there original purpose to hold chalk cubes, or are these recycled from something?