Haifu II booster increases the elasticity of the sponge, thus increasing ball feel, speed and spin. It is matching ITTF VOC <0.5 rule. Its effect lasts for 4-8 weeks. The booster is not an adhesive. Bonding booster covers with high viscosity adhesive is recommended for best results. Premium quaity. It offers more sensation to your game! Choice for top players.