Multiple franking with 28 stamps on giant cover in the size 35 x 26.5 cm, franked by Michel no. 13a (12), 14d (6), 15 (4), 16a (4) and 18g (2), with circle date stamp "HELIGOLAND JY 11 1890" to Mainz. Envelope / stamps with slight trace of creases. Two more, formerly franked stamps, missing. The Michel value the 28 stamps amounts lots used already 960.- Euro. The kind large size mailings are very rare! Certificate with photograph Müller "interesting exhibit from the Roesner correspondence. "