The £7.65 up to 500g Special Delivery postage stamp with self-adhesive gum was issued in 2014. These stamps guarantee next day delivery with standard insurance cover included of £500. All you need to add is a silver barcode tracking label which are available from all Post Offices.
The stamps being offered here are a one off special purchase, so when they're gone, they're gone.
Special Delivery stamps are no longer being printed by the Royal Mail, however existing stocks can still be used until stocks are exhausted, or when the stamps become worth more than face value as collectable stamps. These stamps will still be valid for postal use after 31st of January 2023, we have this in writing from Royal Mail senior management.