Parachuting is a dangerous sport that can lead to injury or death. An altimeter is a mechanical (electronic) device that can fail even when properly designed, manufactured, tested, maintained, and used. Failure can occur both during the ascent and descent — it is necessary to use visual height control. Do not trust your safety to the altimeter! An altimeter can only be considered as a height detection device (accessory). The altimeter should only be used as an addition to visual contact with the ground.