Instruments and appliances for aeronautical or space navigation (other than compasses), including gyroscopes, altimeters, attitude indicators and flight instruments.

Aircraft instruments need airworthiness release certificates and are often export controlled; provide serial numbers and records. Measuring and survey instruments are precision goods: pack in padded cases with silica gel, state accuracy class, range and resolution, provide calibration certificates traceable to national standards, CE/BIS marks for electronic units, and keep lithium batteries under dangerous goods rules; some navigation and geophysical instruments are export controlled.