Many choices exist today for the electrician seeking to buy a voltage tester. Following are some important points to take into consideration in making that choice:

• Battery Power. The K-60 does not require a battery. Most of the battery-powered voltage/continuity testers will not measure voltage without a battery. We see this as a significant disadvantage to these type testers. Batteries will, of course, discharge over time and, without care, can corrode and damage the instrument. The K-60 is always ready for use—no batteries required.
• Input Impedance. The K-60 presents an input impedance of approximately 4,000 ohms to the circuit being tested. This is low enough to identify circuits with loose or marginal connections—a very important function of a voltage tester. The battery-powered testers typically have a much higher input impedance, often on the order of 750,000 ohms. In certain situations this could lead to the tester indicating voltage (a good circuit) when, in reality, a bad connection exists in the circuit.
• Dual Indication of Voltage. The K-60 has both a pointer and a light to indicate the presence of voltage—an important redundant system. Other testers usually just have a light to indicate voltage. If the light burns out, or malfunctions, there is no backup system for indicating voltage—a potentially dangerous situation.
• Vibration. In addition to the redundant system described above, the K-60 also vibrates when connected to a live circuit. This feedback is useful in situations where reading the pointer or display is difficult. This feedback actually provides a third level of redundancy, and even more safety, to the dual voltage indication of the K-60 as described above.
• UL Listed. The K-60 is UL Listed and CAT III approved, an important indicator of its continued quality and safety. Other testers are either not UL Listed, or have a pending UL Listing which is no guarantee that a UL Listing is forthcoming.
• Warranty. The K-60 is warranted for two years from the date of manufacture, or eighteen months from the date of purchase, whichever comes first. Other testers have much shorter warranties, usually 90 days to one year.
• Made in USA. The K-60 is 100% made in the USA. It is hand-assembled by Union laborers. Most other testers are built overseas using inexpensive non-union labor.
• Time Proven. The K-60 has been in production for over fifty years. It has an unassailable reputation as the best tester on the market. Other testers come and go, but the K-60 endures because it is the best.

We believe that when all of the above points are taken into consideration the Knopp K-60 emerges as the clearly superior choice.