1. Good product quality. 2. Strict inner quality control management. 3. ... , 4+0.76+4mm, 5+0.76+5mm, 6+0.76+6mm, 6+1.14+6mm, 6+1.52+6mm;8+0.76+8mm, 8 ... +1.52+8mm etc, could be produced as per request ... country.4. Strict inner quality control management.5. Safety package.6. Favorable price but good quality.7.Sincere after-sale service ...