The product described is a block of 4 stamps from Guinea, issued in 1993 and featuring an INVERTED overprint of the Bangkok issue. The stamps showcase a unique WWF and World Chess-Scouts theme, with black colouring and inverted overprinting. This rare find is considered a major error, with perforated edges and mint never hinged quality, making it a highly sought-after collectible for stamp enthusiasts and collectors alike. The vibrant multi-coloured design and exceptional condition of the stamps add to their appeal and value, making them a standout piece in any collection.