The ER-1 was a Naboo-built probe droid designed to operate under extreme temperature and pressure conditions. Repulsorlifts provided the ER-1 with mobility, and the model was also outfitted with high-end sensor, recording, and communications devices. The ER-1 carried twelve deployable biosensors, along with a set of repulsor-powered sensors and recording devices, slaved to the main unit. The peripherals were designed to transmit all data collected back to the droid for analysis.
Master of Sciences Graf Zapalo used three ER-1s designated ER-1A, ER-1B and ER-1D, to help map the planet's mysterious ocean tunnels. A fourth ER-1, carried by a Mantaris Medium Transport, was dispatched to Ohma-D'un, where it aided in the colonization efforts.
- Star Wars Episode I: The Gungan Frontier (First appearance)
- The Official Star Wars Fact File 104 (German Edition - ZAP2, Graf Zapalo)
- The New Essential Guide to Droids