Later helically scanning recorders instead usually use a method called slant-azimuth recording, also called symmetric phase recording. The head drum usually contains two heads with the magnetic gap of one head slanted slightly leftwards and the magnetic gap of the other head slanted slightly rightwards. (The slant of a magnetic head is referred to as its "azimuth" adjustment). Because of the alternating slants, each head will not wrongly read the signal recorded by the other head and the stripes can be recorded immediately next to each other, alternating between left slant on one television field and right slant on the next television field. (In practice, it's not uncommon for the recorded stripes to overlap somewhat). Later machines including the JVC VHS and the Sony Betamax use slant-azimuth recording as well as all later machines and their digital derivatives.