The Hubbell Twist-Lock Tester is an exclusive patented design that easily tests the circuit condition without the need for traditional measurement techniques. Whether it is a contractor, electrician, or entertainment stage crew, knowing that power is present at any receptacle or connector is critical. By plugging the tester into an outlet, an LED output will immediately provide the state of the circuit. An easy to read card is provided with the tester, to help determine if the connections are made properly and in the correct position. This unique NEMA configuration ensures that the proper connection was made through an easy to read output display. It also easily attaches to a tool belt so it is available when needed.