Aden. 1941. Registered envelope addressed to India bearing Aden SG 21, 2 1/2a blue (pair) tied by Aden double ring with matching registered label and 'Opened by Censor/PC 22' label tied by framed 'Passed Censor/By/ No 1/Aden' hand-stamp in violet with 'Passed by Censor/C 20' cachet on face. Very fine.