1. We have the strong advantage of quality and cost control. We runs completely according to ISO9001 quality system. 2. We can ensure the quality can meet professional test as Black Test, Gray Test, Ghost Test, Blank Test and Word Test. 3. All of our products are 100% pre-tested prior to leaving the factory, Defective rate below 1%. 4. We guarantee for 100% replace or refund for any defective products.