1. Look at the appearance, smooth, no dry yarn, cracks and other phenomena. 2. Look at the glass fiber, whether the layers are clear. If you can count the layers of glass fiber, it is proved to be alkali-free glass fiber. 3. Strength test, directly cut the specifications of 3*1 cm, put pressure on the car, and get immediate results. If it is a high-quality grille, it will only be slightly bent, while the inferior grille will produce a clicking sound, which means that the glass fiber has begun to break. The grille produced by Zaozhuang Fenghe Weiye new building materials has excellent quality and can be used selectively.