1901 (20 Apr) Cover to Royal Engineers, Tangku, f.w. Indian QV ovpt. C.E.F. 3p in pair, tied by FPO No. 4 cds. In combination with Coiling
1901 (20 Apr) Cover to Royal Engineers, Tangku, f.w. Indian QV ovpt. C.E.F. 3p in pair, tied by FPO No. 4 cds. In combination with Coiling Dragon surch B.R.A. 5c, tied by “RAILWAY POST OFFICE / TIENTSIN” circular seal in violet. On reverse with another type of FPO No. 4 cds. 1901.4.20 寄塘沽皇家工兵團封，貼印度維多利亞女皇像加蓋“C.E.F.”3派雙連，銷英軍第4局日戳。加貼蟠龍改值B.R.A. 5分，銷“RAILWAY POST OFFICE / TIENTSIN”紫色圓戳。背面鈐另一樣式之英軍4局日戳。
