Walmart offers Camco Stackable Miniature Ice Cube Tray for Mini Fridges, RV/Marine Freezers, Dorm Freezers and Small Freezers, (2 Pack) (44100) for $9.05 with free shipping.

Product Description:
Camco RV Mini Ice Cube Trays fit perfectly into RV, marine or dorm freezers. They provide small size cubes for quick freezing and are easy to use.