Explanatory notes
… not optically worked, of heading 70.09, or mirrors of base metal or of precious metal, not being optical elements … purposes (laboratory research work, analysis, astronomy, etc.), for specialised technical or industrial purposes …Legal note
… not optically worked, of heading 70.09, or mirrors of base metal or of precious metal, not being optical elements … use exclusively in implants in medical, surgical, dental or veterinary sciences are to be classified in heading 90.21; … for adjusting work or tools on machine-tools or water-jet cutting machines, of heading 84.66, including fittings …