Stampless 'FOAS' cover with circular 'HQ 33 MAINTENANCE TASK FORCE (GREF)' cachet in violet with F.P.O. No. 659 cds on reverse dated 13.2.1971. Addressed to 'Inspectorate of Works, HQ DGBR Kashmir House DHQ, P.O. New Delhi 11'. The GREF was heavily involved in protecting India's borders during the 1971 India-Pakistan War.