This part of ISO 12858 specifies the most important requirements of telescopic tripods for surveying instruments and the connection between instrument and tripod. The requirements in this part of ISO 12858 enable instruments and tripods of different manufacturers to be joined to one another, without prejudicing their performance and their usefulness. This part of ISO 12858 is applicable to tripods which are used for levels, theodolites, tacheometers, GPS equipment, EDM instruments and in combination with targets, reflectors, antennae, etc.