Instructions Soldiers with the 20th Chemical, Biological, Radiological, Nuclear and Explosive Command joined other volunteers in the Aberdeen Proving Ground, Md., area to volunteer their free time and personal 3D printing capabilities to print and create face masks for donation to hospitals and health care workers across the nation combating COVID-19. SHARE: Download: Full Size (0.32 MB) Credit: Rebecca Nappi, Army VIRIN: 200510-A-HF386-1003.JPG Photo Gallery