Vo'cume projector

The Vo'cume was a device of Goa'uld design.

Overview
These machines were small hand helded devices that were roughly cylindrical in form. Internally, they contained a holographic projector making it capable of displaying a arge three-dimensional image which was pre-recorded.

The Goa'uld used the vo'cume as a way of summoning troops, giving orders, authorising spokepersons or dispensing other messages to the Jaffa legions. The use of this device during battlefield operations was strictly forbidden under the rule of engagement.

History
Apophis provided a training camp on P89-534 with a vo'cume so his orders were followed as they trained in techniques for them to infiltrate Earth.

Major Samantha Carter managed to interface with this vo'cume and use it's holographic technology to display the final moments of Apophis before his death when Sokar attacked the SGC for the former System Lord. This resulted in his followers realizing that the Goa'uld was not a god which ended the hostilities towards SG-1.