Five lengths, one decision
You can commit for one month, three months, six months, a year or two years. That is the whole menu. A short term does not give you fewer channels, fewer devices or slower support, so nothing about the service shrinks when you choose one. Each length is also paid once, in full, for the period you picked: nothing recurring is set up against your card and nothing continues by itself, which is why the end date matters more here than it would with a rolling account.