Encourage your kids to play outdoors with the Rock Lock 4 x 4 Sandbox. This sandbox is constructed from high-density polyethylene that will not crack chip or fade no matter the weather. Simply slide the four side panels into place and lock them together with the included spikes. Assembly is that easy. The sandbox also has a 10 year guaranteed UV-stabilized HDPE. Designed for smaller backyards this sand box measures 4L x 4H feet and holds 800 lbs. of sand.