Under the contract, Metro originally agreed to purchase 428 7000-series railcars, both to replace its 1000-series cars and provide service for the new Silver Line. In April 2013, Metro elected to exercise an option in the contract to purchase an additional one hundred cars to replace its one hundred 4000-series cars, which it decided do not warrant being overhauled in light of chronic mechanical issues. In September 2013, Metro announced it exercised another option under the contract to purchase an additional 220 railcars, bringing the total order to 748 railcars. In total, the new 7000-series railcars currently make up more than half of Metro's rolling stock as of 2020. In November 2013, it was reported that the first four cars would arrive before the end of 2013 and that they would then be tested for 30 weeks, allowing Metro to troubleshoot any issues before full production begins.