Aterian PLC signed a definitive Earn-In Investment and Joint Venture Agreement with Rio Tinto and Kinunga Mining in Rwanda for the exploration and development of lithium and by-products. Rio Tinto has an option to invest US$7.5 million to earn up to a 75% interest in the Licence. Cash consideration of US$300,000 and capped Net smelter return ("NSR") granted over the Project. The Project has 19 identified pegmatite zones over 2,750 hectares in Rwanda, with good infrastructure. This transformative deal highlights Aterian's ability to identify world-class deposits in critical minerals like lithium. Lithium is crucial for global electrification goals, with rising demand forecasted. The Agreement demonstrates potential for Aterian shareholders and the Rwanda mining sector. Rio Tinto will act as the operator for the Project. The HCK Project holds promise with strategic mineral assets, and future developments aim to replicate this success in other concessions.