1. If we send a wrong (less) quantity by mistake , we will supply the quantity which is deficient , also we will be responsible for the shipping cost.2. If the goods damage during shipping , the express company will be responsible for this , but we can also supply you some free units to replace if we have enough spare, you just need to pay the shipping cost .

If some of products have problem and the order is a repetitive one , we will provide extra quantity for free in next order .