The BESANTEK BSTLAN11 Handheld 4-In-1 Cable Tester is a palm sized unit with four different testing ports: RJ-45, RJ-11, USB and BNC, for the testing of today's most popular media. This unit can be used to verify the condition of cables, both before and after their installation. The passive module can be separated for testing the remote end of installed network cabling. One button testing offers easy operation and multiple LEDs give clear testing results. The units will also automatically shut off when not in use.