... cell foam 1.Anti-collision and heat insulation 2.Smooth Surface 3.no toxic.durable in water ,could filter air,dust Closed cell ... foam 1.Anti-collision and heat insulation2.Smooth Surface3.no toxic.durable ... stand some press ,closed cell .,10-60ppi ,good elasticiry ,no toxic.durable in water ,could filter air,dust.1 .pu foam material2 ...