Constructed of Velostat™ material made of polymeric foil (polyolefines) impregnated with carbon black, 3 13/16 in. dia x 4 11/16 in. high Velostat Round Containers (item number 57018) are used for static-safe storage, kitting, and in-process handling and transporting of static-sensitive assemblies and devices. Velostat black, electrically conductive material controls static charges by eliminating ESD.