Test and measurement involves electricity. Terminal blocks are widely used in T&M applications. Terminal blocks are used to easily test and measure the voltage and/or current of a specific circuit. Test disconnect terminal blocks are used for measuring control regulatory circuits and for current transformer connection applications. Test blocks allow an operator to interrupt the circuit and test the voltage or current passing through. These specialized blocks provide a clear advantage for devices having utility instruments and associated transformers. Test blocks allow for an adapter accessory to be inserted for quick and safe use of the testing equipment. This adapter comes in contact with the circuit, which allows the user to test the voltage with the accessory.