We used to use it to get free phone calls. It had an old-style BT phone attached to it (possibly with an acoustic coupler, I don’t remember exactly). The phone didn’t have a dial on it, the front was just blank where the dial should be. What it did have, however, was a cradle and pulse dialling. So you could take it off-hook and hammer out the numbers morse-code style on the cradle. Pheer our l33t skilz