An unofficial but widely used Motor or Mechanised Transport proficiency badge used in WW2. Still in use by TA units in the 1960s.
This example 85mm wide, 52mm tall. Black, white and grey thread on a khaki background. A grey wheel with white spokes, white wings emanating from the centre. Above this the letters ‘M.T.’ in white thread.
See: Edwards D. & Langley D., British Army Proficiency Badges (Wardley Publishing) 1984, page 128-129