Minneapolis-based 3M manufactured these dual-ended earplugs for hearing protection from close range firearms and other loud impact noises. Due to the defective design, the earplugs can slightly loosen and subtly move out of the ear canal just enough for the loud sounds to cause hearing damage. 3M knew of these design defects, but knowingly sold them to the US military from 2003-2015.

​Service members and combat veterans have reported multiple side effects including:

• Hearing loss
• Tinnitus, or ringing in the ears
• Permanent hearing damage
• Deafness

3M agreed to pay $9.1 million in a False Claims Act lawsuit to settle allegations that it knowingly supplied the United States military with defective earplugs.