All of the lenovo laptop adapters have the protection function of over charge and over discharge, over heat, over current etc. We have passed the CE authentication of Europe, and it produces according with the UL standard, all of lenovo adapters can be passed easily through the test of short-circuit, over voltage, low voltage etc. And our lenovo adapter has been tested on related lenovo laptop to ensure that them are 100% compatible original product. In addition, we also provide 30 Days Money Back and Two Year warranty to ensure your confidence with our lenovo laptop adapters. We look forward to cooperating with you!