Dianchi - D National Orange Sponge Is a sticky rubber that is recommended by, among others, China's defensive player Houying Chao. With a unique Energy-Enhancement Technology from Dianchi that generates more power than the usual Chinese sponge. The harder sponge comes into its own more with harder hits and gives a faster, stronger kick and gives more screw in the loops. Sponge thickness: 2.1mm.