Block Inc., the fintech firm led by Twitter co-founder Jack Dorsey, has unveiled what it says is the first Bitcoin mining application-specific integrated circuit manufactured in the United States. Branded “Proto,” the 3-nanometer chip powers a new line of modular machines dubbed Proto Rig and Proto Fleet, which run on open-source software and deliver energy efficiency of up to 14.1 joules per terahash. Dorsey called the device the “greatest bitcoin miner of all time” at the product launch on Thursday. The hardware is designed for a 10-year service life and features swappable hashboards, a change Block says can trim miners’ upgrade costs by 15-20% per cycle and reduce electronic waste. By bringing chip production onshore, the company aims to loosen China’s long-held grip on the mining-equipment supply chain and strengthen the resilience of the Bitcoin network. Mining firm Core Scientific has already placed an order representing about 15 exahashes per second of capacity, according to Block. The debut arrives as U.S. policymakers push for more domestic control over Bitcoin issuance and as miners grapple with rising power costs and reduced block rewards after last year’s halving. Block shares slipped roughly 1% in afternoon trading, while Bitcoin changed hands near $118,200, down about 3% in the past 24 hours.