DataShark RJ45 Network Tester Kit The DataShark RJ45 Network Tester Kit will take the guesswork out of networking and cable installation. This handy tool is small enough to fit in a pocket, laptop bag, or tool kit. The DataShark RJ45 Network Tester Kit reliably identifies Good connections, Opens and shorts in the network signal, and cross-connections. Quickly and easily test your computer patch cords or installed cable runs to verify good connections or to troubleshoot problems. DataShark is part of the connectool family of brands.