A bouldering mat or crash pad is a foam

Foam

-Definition:A foam is a substance that is formed by trapping gas in a liquid or solid in a divided form, i.e. by forming gas regions inside liquid regions, leading to different kinds of dispersed media...

 pad

Pad

Pad or PAD may refer to:* Writing pad, a book of paper* Sanitary pad, a device worn by a woman during menstruation-Transportation:* Launch pad, an area where spacecraft lifts off* Helicopter landing pad...

 used for protection

Protection (climbing)

To make climbing as safe as possible, most climbers use protection, a term used to describe the equipment used to prevent injury to themselves and others.-Types of climbing:...

 when bouldering

Bouldering

Bouldering is a style of rock climbing undertaken without a rope and normally limited to very short climbs over a crash pad so that a fall will not result in serious injury. It is typically practiced on large natural boulders or artificial boulders in gyms and outdoor urban areas...

. There are various sizes and makes, but the most common type is a folded mattress, 8 to 10 centimetres thick (3 to 4 inches), that when unfolded measures about 1 x 1.3 metres (3 x 4 feet). Bouldering mats often have shoulder straps so as to easily move it between boulders. Bouldering mats often come in either dual or triple density foam inners to provide differing levels of support with the bottom or middle being the softer. With the higher density foam at the top this will prevent the climber

Climber

Climber may refer to:*Climber, a participant in the activity of climbing*Climber, general name for a vine*Climber , a robot that goes upward or downward on a track*Climber , by Nintendo...

's foot from sinking through the foam and either gaining impact on the floor or getting a foot stuck in the mat which would increase the chance of injury. Mats are often used to cover dangerous sections of the ground below a chosen climb such as protruding rocks or grass tufts.

Usually the crash pad is paired with a couple of spotters in order to ensure the safety of the climber.