Although they can complete their work, but in my humble opinion these guys don't know much what they are doing and they don't seem to care to inspect or verify whether the work has been done (correctly) or completed. You go back home and upon arrival you realize you paid for the work that has not been done (properly) or at all. Always demand them to demonstrate to your that your equipment works and how it works before you pay for it and before you take it home. Not recommended.