The Volunteer Air Detachments, were groups of ladies from the Red Cross, St John's Ambulance and St Andrews Ambulance seconded to each of the three services to assist in medical treatment where needed.  During WW2 4000 served with the Royal Navy, 4028 with the Army and 413 with the Royal Air Force, and were split into two classes - 'Mobile' and 'Immobile'.  Those classed as Mobile could serve anywhere they were needed, those classed as Immobile would served close to their home.  Aside from nursing, VADs served as Cooks and Clerks, and those with professional qualifications as Pharmacists, Radiographers, Lab Assistants and Opticians.  Uniform was a dark blue tunic and cap with Red Cross insignia, and qualification badges, with specific badges applicable to the service they were serving with (facing eagles to the tunic collars (RAF); Regimental badge (Army) or Anchor (Royal Navy))

A nice and rather scarce VAD 'Immobile Sleeve Badge'.