In our outdoor pens, we use these large "fast food" trays for feeding to prevent tortoises from eating gravel or dirt stuck to their food. They have a very low rim around the perimeter to contain food but not so big that the tortoises have a hard time getting in and out of the trays. Sized at 14"x10", we use them for all tortoises in outdoor enclosures. They can also contain shallow water, but the surface must be extremely flat because the rim is very low (it spills out the low side). Great for use with moistened Mazuri tortoise diet or small chopped veggies.