GPS Transmitters are powered blocks that build the network behind Slimefun's GPS travel tools. They belong to the player who placed them and must stay supplied with energy to remain online.
When a transmitter has enough power, it registers itself as active in its owner's GPS network. Your GPS network complexity is based on the transmitters you own, which is why transmitters matter for advanced travel setups.
Higher tiers are stronger versions of the same idea: better GPS infrastructure for teleportation and waypoint systems.
Place transmitters as part of a powered base or travel network and keep them connected to your energy system. They support tools and blocks like the GPS Control Panel, Portable Teleporter, and GPS Teleporter Matrix.