The Tok'ra hologram projector are small devices used by the Tok'ra to generate holograms.
Background[]
These small hand held hemispherical devices are capable of being carried by a Tok'ra operative and used to generate holographic representations used in briefings. They were considered remarkable by 20th century Human standards. It functions by projecting a hologram but without the need for silver-halide coated plates or photopolymer film. These holograms were made of light and allowed users to pass their hands through the projections.

Projection of the System Lords hierarchy.
History[]
After the defeat of Hathor, Tok'ra operative Jacob Carter/Selmak travelled to Earth in order to enlist the aid of Stargate Command to track down a fugitive Goa'uld. Meeting in the briefing room, Carter/Selmak used a hologram projector to provide a visual representation of the System Lords hierarchy where he revealed that Tok'ra intelligence had lost trace of Setesh since the burial of Earth's Stargate. Thus, the Tok'ra High Council suspected the fugitive Goa'uld was hiding on Earth since his attempted overthrow attempt of Ra. (SG1: "Seth")