1. Appearance: In addition to special big air, chaotic outside air sponge, the general appearance of the more delicate sponge pores as small as possible.

2. Feel: can quickly rebound, fluffy sponge is better, feeling dead sponge of lemons.

3. Tensile properties: a good sponge at least 80% of the tensile elongation, reach for the low-grade goods.

4. Temperatures: normal sponge has a little odor, but if it taste foul excruciating for the use of inferior materials.

5. Tear Strength: easy to tear a good sponge and gently finger a little on the break is, of course jerry