When you need to get the job done on a budget with product you know is going to work we've designed this product with Contractors in mind. Test your cables before you start the new or existing project to save time and aggravation. Tests Continuity of HDMI™ cables including Ethernet. Requires: 9V Battery WARNING: The CS-HDMTESTER is for cable testing only! Do not connect directly to electronics, as damage will occur.