A multi-tool (or multitool) is any one of a range of portable, versatile hand tools that combines several individual functions in a single unit. The smallest are credit-card or key sized units designed for carrying in a wallet or on a keyring, but others are designed to be carried in a trouser pocket or belt-mounted pouch.
Among the earliest contemporary examples is the Swiss Army knife as supplied by makers Victorinox and Wenger. The actual version supplied to the Swiss army includes a knife blade, a reamer, a bottle-opener–screwdriver–wire stripper, and a can-opener–screwdriver. Besides Victorinox and Wenger, many other manufacturers now make similar knives.
Other versions may include items like a nail file, tweezers, folding scissors, a tooth pick, a magnifying glass, screwdriver bits and others. There are also versions that have special tools for specific sports or outdoor activities like golf, horseback riding, hunting or fishing. Versions intended for cyclists may have a selection of allen (hex) keys, a selection of wrenches, screwdrivers, a spoke key, and a chain-breaker.
Models like the Wenger SwissGrip, Wenger Pocketgrip, Al Mar 4x4, SOG ToolClip, Snap-on and CRKT Zilla-Tool are similar in style.
In 1983 Tim Leatherman sold his first "Pocket Survival Tool", larger and more robust than a pocket-knife based tool, and incorporating a set of needle-nosed pliers in a balisong-style mechanism. Too large for most pockets, it came with a belt pouch. Today, Leatherman Tool Group manufactures and markets a variety of multi-tool models.
"Leatherman" is now often treated as a genericized trademark for the similar multi-tools now available from makers such as Coleman, Gerber, Kershaw Knives, Schrade, SOG Knife, Victorinox, Craftsman - along with many unbranded types produced in low-cost production regions, and smaller mini and micro units are often small enough for pockets or even key rings.
In recent years, a number of urban and outdoor multi-tools have sprouted offering non-traditional tools one would not expect to find in a single unit.