Snap-On Inc. was founded in 1920 in Milwaukee with 13 operational plants in several states across the United States. Snap-On manufactures items that range from digital multimeters, test leads, circuit testers, videoscopes, infrared thermometers, and digital multimeter accessories. With a customer base in over 130 countries, Snap-On works to produce hand-held electronic diagnostic tools for computer systems used in cars and heavy-duty vehicles. Snap-On originally started as a manufacturer of equipment for vehicles in the early 20th century, but over time Snap-On grew to service industries in the marine, aviation, and railroad industries.