An emergency hammer is a safety device used in vehicles to break through window glass in an emergency.

It is a simple tool with a plastic

Plastic

A plastic material is any of a wide range of synthetic or semi-synthetic organic solids used in the manufacture of industrial products. Plastics are typically polymers of high molecular mass, and may contain other substances to improve performance and/or reduce production costs...

 handles and steel

Steel

Steel is an alloy that consists mostly of iron and has a carbon content between 0.2% and 2.1% by weight, depending on the grade. Carbon is the most common alloying material for iron, but various other alloying elements are used, such as manganese, chromium, vanadium, and tungsten...

 tip. Its primary use is for breaking through vehicle windows, which are often tempered, in the event of a crash which prevents exit through the doors. They are commonly found on public transport

Public transport

Public transport is a shared passenger transportation service which is available for use by the general public, as distinct from modes such as taxicab, car pooling or hired buses which are not shared by strangers without private arrangement.Public transport modes include buses, trolleybuses, trams...

, in particular train

Train

A train is a connected series of vehicles for rail transport that move along a track to transport cargo or passengers from one place to another place. The track usually consists of two rails, but might also be a monorail or maglev guideway.Propulsion for the train is provided by a separate...

s and bus

Bus

A bus is a road vehicle designed to carry passengers. Buses can have a capacity as high as 300 passengers. The most common type of bus is the single-decker bus, with larger loads carried by double-decker buses and articulated buses, and smaller loads carried by midibuses and minibuses; coaches are...

es. The example pictured also illustrates a cutting tool at the other end of the hammer. This is used for cutting through seatbelts in the event that they are inhibiting a passengers exit.

Emergency hammers are also known as bus mallets, dotty hammers, safety mallets, and bus hammers. Most emergency hammers are attached to a cable or an alarm device to deter theft

Theft

In common usage, theft is the illegal taking of another person's property without that person's permission or consent. The word is also used as an informal shorthand term for some crimes against property, such as burglary, embezzlement, larceny, looting, robbery, shoplifting and fraud...

or misuse.

Emergency hammers can be purchased by consumers to store in their personal vehicles to provide a means of escape should the doors become unusable, such as in a collision or if the vehicle falls into water and is sinking.