What is the purpose of the STOP sticker on the all-metal probes?

Straight, non-bent whole-metal probes usually have no stop sleeve. Therefore the STOP sticker indicates how far the probe has to be inserted in order to function properly.

ATTENTION: The old mounting adapter type UN is 20mm shorter than the latest mounting adapter SUN. If a probe with a STOP sticker orginally made for the length of an adapter UN is plugged into a 20mm longer SUN adapter, the STOP sticker is in the wrong position! The probe must then be inserted 20mm deeper than the STOP sticker indicates, otherwise the probe will fail. In such cases the sticker should be replaced, esa systems will provide you with a spare sticker. The function of all instruments connected to a probe must be checked before each take off!