If you are interested in our products and want us samples, we can do some samples as your requests. But you need to pay us the sample fee, when you give us the order, then we can return the fee back to you. And we will send more spare parts to you, if there's some problem with the products, you can change these spare parts by yourselves, but we can't replace a new one. We can promise the quality of our products, i think you can trust us.