A caver deep in the cave wishes to send a message to the entrance. They look for an already bared section of wire, possibly marked with flagging tape. If there is none nearby they use a small pocket knife to bare the insulation and expose some wire. Holding the Michiephone in their hand they switch it on, placing their other hand on the ground as in the photo. To send a message they push the Press-To-Talk button, it's labelled PTT. Speaking in a normal level voice they ask if there is anyone listening as they have a message for the entrance team. They then release the PTT button so their unit can receive any reply. A few seconds later a reply comes back from the Entrance.
The cavers are now communicating clearly and easily. Other cavers with Michiephones can also connect to the wire and find out what's happening.