Great Britain King George V "Seahorses" 1915 10s Deep blue, SG411.
A very fine well centred unused original gum example printed by De La Rue.
The most difficult of the shades to find of the famous Seahorse issues and one of the all-time classics of GB philately.
GB Specialised Catalogue Number: N70(2).
The SG catalogue price for this stamp is £5,500