3M has agreed to pay over $6 billion to settle lawsuits from hundreds of thousands of military service members who claimed they developed hearing problems after using the company’s earplugs, according to reports. A person familiar with the agreement told Reuters that the funds will be paid out over five years to settle the litigation, which had grown into the largest single mass tort in American history. The Combat Arms earplugs were manufactured by a company which 3M bought in 2008—Aearo Technologies—and used in both training and combat by the U.S. military, including in Iraq and Afghanistan. The lawsuits alleged that the company had concealed design flaws and distorted test results, with the earplugs ultimately failing to protect users’ hearing from noise damage. News of the settlement comes after 3M reached a tentative $10.3 billion settlement in June to resolve litigation relating to “forever chemicals” polluting water systems.