Gladon PWF18 1/8" x 42" x 125' Waveless In Ground Pool Wall Foam 2 lb: Add years of life to your pool liner! All wall foams are NOT created equal! Compare Gladon's high quality flat foam to any others and you will see the difference. Wall Foam adds insulation to your pool to keep the water warmer and save energy. Use on metal, concrete, or wood to get smooth pool walls. Do you need special lengths and widths? No problem! Gladon does all of its own slitting and rewinding in house.