2 Lbs 3/16" X 3/8" Cylinder Ceramic Rock Tumbling Media for Stone Tumbling and Polishing

They're exactly what you asked for. And yes you can fit them all back in the same jar after you take them out. Might not seem like it but you can.

This beads are small so they can carry grit into tight spots and do a great job providing cushion for the stones in the last two tumbling rounds of 4.

Experimenting with tumbling "sea glass", and was glad another netizen clued me in to the need for this, as well as the required grit. This adds a cushioning effect during tumbling, and allows more space for the grit to get into everywhere necessary. These are reusable for several tumbling sessions, depending on the grit. Very pleased with this purchase.

Took a bit longer than I expected for delivery but the product works great and is a staple in my tumbler

I was using plastic beads for my last two tumbling sessions, and was not able to achieve the shine I had hoped for. I used these ceramic pieces and finally achieved the polish rocks I hoped for. They are easier to use than the plastic beads and they don’t pick up any of the grit color like the plastic beads did.