when the sound waves incident into it, it can cause gaps in the air vibration; the viscous drag due to air friction and pore walls, so that a considerable part of the sound energy into heat energy has been consumed.

Details:
1.have good quality .
2.have different kinds of shapes and different colors

3.Packing: according to customer's request.

4.Special requirements on design, logo and color are welcome. OEM design is available

5.Super quality and competitive price are ensured

6.Fashionable and attractive promotional/gift/toy products.

7.Frankly speaking, it's really a good choice for you