Knopp K-3 Phase Sequence Indicator, 60-600V With Case. Made in USA. Very nice #3

The Knopp K-3 Phase Sequence Indicator is a high-quality, American-made tool designed for testing and measuring the phase sequence of electrical systems. With a voltage range of 60-600V, this indicator is perfect for industrial and commercial applications. It comes with a convenient case for easy storage and transport. The Knopp brand is known for its reliability and accuracy, making this product a valuable addition to any toolkit.