SEM (Scanning Electron Microscopy) tests are conducted through analysis of the residues which have been collected on sticky metal stubs. These kits come in a 4 stub stub application and includes instructions, information sheet, gloves, security seals, and an envelope. Envelope measures 6" X 9". GSR Collection Kit Contents: 4 Carbon Disks (SEM) 1 Pair Protective Gloves Security Seal 6" x 9" Envelope Information Sheet Instructions Custom configurations of these kits are available on request.