... in water ,could filter air,dust Closed cell foam 1.Anti-collision and heat insulation2.Smooth Surface3.no toxic.durable in water ... toxic.durable in water ,could filter air,dust.1 .pu foam material2, reticulated, mesh,10ppi-60ppi,3 good resilient, good air ... ect. 6 UV- protection, environment , have passed SGS and AOV EPE foam tube