This hammock has slightlly thicker string used in its construction. It is a large hammock similar to the #20 but the thicker strings make it a bit more resistant to rough treatment. A good backyard family hammock. The string used to make this hammock is more expensive and with its mercerization is stronger, more color fast, has brighter more vibrant colors, and in these finely woven hammock is much more resistant to snagging. These hammocks come in a variety of bright colors with a very tight weave in the old Mayan tradition. These hammocks will last up to twice as long a a standard hammock because of the quality and strength of the mercerized cotton string.