In the 1980s, the Greek company SIBER Telecommunications S.A. introduced the DT-2 digital call meter. The company was active in Greece during the 1980s and 1990s, supplying telecommunications equipment and providing technical support. It replaced the analog call meters used in previous years. It is made of light-grey plastic. On the back—the side facing the customer making the call—there is a display showing the cost of the call in drachmas. Conversely, the front side features three buttons and a display; depending on how many times the left button was pressed, the screen would alternately show the call units, the cost of the call in drachmas, or the cumulative total of units. Pressing the middle button cleared the data from the previous call, allowing a new one to be made. Pressing the right button—labeled “BLOCK”—restricted the phone to local calls only; this status was indicated by a padlock icon appearing on the left side of the screen. On the base of the device, there is a sticker showing the required telephone network wiring configuration and the serial number. Its dimensions are 6.5 cm x 13.5 cm x 14 cm. The sole customer for these devices was the Hellenic Telecommunications Organization (OTE S.A.), which managed the public telephone network.