What household item make the characters of "Steins; Gate" travel through time?

In the anime series Steins;Gate, the household item that allows the characters to travel through time is a modified microwave. The microwave is retrofitted with a phone microwave system, known as the PhoneWave (name subject to change), which functions by sending electric signals to the phone wave (name subject to change) which then creates a small enough black hole to break the barrier of time and allow for time travel. This unique modification of the microwave is the key tool that drives the plot of the series and enables the characters to manipulate the past and future events.