... foam 1.Anti-collision and heat insulation 2.Smooth Surface 3.no toxic.durable in water ,could filter air,dust Closed cell foam ... toxic.durable in water ,could filter air,dustClosed cell foam could stand some press ,closed cell .,10-60ppi ... in water ,could filter air,dust.1 .pu foam material2, reticulated, mesh,10ppi-60ppi,3 good resilient, ... protection, environment , have passed SGS and AOV EPE foam tube