New and improved quality with anti-slip rubber profile. Plastic hemispheres challenge anybody's balancing skills. You can try to walk on the hemispheres with either side - the flat or the round side - up. They do not slip as they are heavy and filled with sand. Can withstand damp conditions if left on the playground overnight. Colorful set of six in red, blue and yellow; two of each color. 220 lbs Weight Limit.