I searched all over my yard for something that would work that was just right. I found in the shed about 10 of the kids 3 foot long sleds. Worked perfect, for the younger ducks I put stones on the inside edge so they can climb out and a ramp on the outside. The bigger pekings use there sled to swim in, and prefer it to the sandbox turtle i filled with water for them. It fits all 5 of the big ones and a separate one for the other 8 younger ones at three weeks old.