$20每个月，不是unlimited nationwide 4G。网站没说是什么技术，
If you frequently upload pictures and send attachments via e-mail, 2 GB is
recommended for you.
You won’t incur overages if you exceed your plan’s allotment of high-speed
data, but your data speeds will be reduced for the rest of your billing
cycle.
Limited-time offers; subject to change. Taxes and fees additional. Domestic
only. Compatible device required; not all features or plans available on all
devices. Unlimited features for direct U.S. communications between two
people. Credit approval, $35 per line activation fee and two-year agreement
with up to $200/line early cancellation fee required; deposit may apply. If
you switch plans you may be bound by existing or extended contract term (
including early cancellation provisions) and/or an up to $200 fee. You may
be unable to switch to some plans. Additional requirements may apply to
business customers; Premier and other business/association discounts may not
be available. Regulatory Programs Fee (not a tax or government-mandated
charge) of up to $1.61 per line/month applies. Taxes approx. 6%–28% of your
monthly bill. Overage usage extra; partial megabytes rounded up. For
unlimited data plans, full speeds available up to monthly data allotment;
after allotment used, speeds slowed to up to 2G speeds for remainder of
billing cycle. For 200MB plan, overage of $0.10/MB charged to postpaid
customers after monthly data allotment is used; FlexPay customers may not
exceed 200MB allotment. Web/Data: Your data session, plan, or service may be
slowed, suspended, terminated, or restricted if you use your service in a
way that interferes with or impacts our network or ability to provide
quality service to other users, if you roam for a significant portion of
your usage, or if you use a disproportionate amount of bandwidth during a
billing cycle. You may not use your plan or device for prohibited uses.
