The design of the Landis & Gyr cards have been used for several years, and many reprints. However, they can be easily distinguished by control number on back; moreover, the blue 60 units card with code 810A, the first issued, is easy to recognize as it had printed for mistake the words Adwin asa instead than Adwen asa. The 240 units card, with code 810B was issued with a mintage of just 20,000, and never reprinted, so that it is now very hard to get. In 1994, Ghana P&T adopted a telephone system based on chip cards, which is still in use.