Radiation Shielding Materials by Pitts Little Pitts Little Corporation is a manufacturing company that specializes in the design, fabrication, and installation of various types of radiation shielding materials, including lead lined doors, leaded Pitts Little Corporation is a manufacturing company that specializes in the design, fabrication, and installation of various types of radiation shielding materials, including lead lined doors, leaded xray glass, and lead lined drywall.