Manufacturer profile
About Klein Tools
Reviewed 2026-07-26
Klein Tools is a family-owned manufacturer of professional hand tools and related equipment for electrical, utility, construction, and industrial work. The company does not specialize only in multimeters; this manual page is narrower than the business and covers its digital meters, clamp meters, voltage testers, receptacle testers, and other electrical diagnostic tools.
History
Mathias Klein established the business in Chicago in 1857 after making a replacement half for a telegraph lineman's broken pliers. Klein Tools grew with the telecommunications and electrical industries and remains operated by the Klein family. Its wider portfolio includes pliers, cutters, screwdrivers, fish tapes, storage, safety equipment, and many other professional tools in addition to electronic test products.
The manuals indexed here represent the measurement portion of that much larger catalog, including MM-series digital multimeters, CL-series clamp meters, and ET-series electrical testers. Corporate acquisitions such as Vaco, Mumme Tools, Ergodyne, Wattmaster, and Alco form part of Klein's broader history but are not necessary to explain these meter manuals. The page therefore distinguishes the company's overall hand-tool identity from the focused electrical-test scope relevant to archive users.
Equipment specialties
- Digital multimeters
- Clamp meters
- Voltage and receptacle testers
- Electrical measurement tools
- Professional hand tools for electrical trades
Sources
- History — Klein Tools, Inc. (accessed 2026-07-26)
- American Manufacturing — Klein Tools, Inc. (accessed 2026-07-26)
- Klein Tools — Wikipedia (accessed 2026-07-26)