1. Helmets visor visible light transmittance, impact resistance;
2. The strength performance of helmet wearing devices;
3. The energy performance of helmet collisional absorption;
4. The helmet antipenetration performance.
At the moment, the purpose to wear a cycle helmet is for weatherproof, sun-block, protection against cold by most riders, the other one is to avoid the inspection from traffic police. But they forgot the main function of helmet since its very important function is to protect our personal safety. We should check and buy the helmet with international safety standard.