 Radiation cannot be detected by human senses. Special equipment is needed to discover nuclear and other radioactive material. The IAEA hosted a technical meeting on radiation detection instruments for nuclear security, experts and manufacturers from around the world are in Vienna to discuss the trends, challenges and opportunities to further improve these instruments and their use. This meeting is important to the IAEA because what we want to hear is from the member state what their exact needs and challenges are with regards to the use of radiation detection equipment for nuclear security purposes. So we brought together the equipment manufacturers and the vendors so we can try to match the capabilities we have now with the needs that we anticipate and don't meet at present so we can use science and technology to improve the effectiveness of detection operations.