Mobile Tuberculosis (TB) X-Ray screening service operating across London at a variety of sites. Aimed at marginalised groups who have difficulty accessing mainstream healthcare. The X-Ray equipment is digital and so both gives instant results and is less intrusive than older units (people do not have to undress). Unit will also try to reach areas where TB is higher than usual, such as prisons and hostels for the homeless. Offers flexible service where possible. May also attend special events.