It was only two days ago that T-Mobile’s new Mobile Broadband no-annual contract plans were leaked thanks to a page on Walmart’s website. Today, we’re managing to get a little better of an idea on these upcoming plans launching on May 21st thanks to some leaked training docs.

Let’s break it down:

• $15 option, 300MB of data good for one week
• $25 option, 1.5GB of data good for 30 days
• $35 option, 3.5GB of data good for 30 days if purchased at T-Mobile stores, Walmart exclusive for 60 days
• $50 option, 5GB of data good for 30 days if purchased at T-Mobile stores, Walmart exclusive for 60 days

Let’s just touch on the 60 day timeframe, which means the time period for the data allotment is good for 60 days if purchased at Walmart. It does not mean that Walmart has a 60 day exclusive on the deal, as they will both be available on May 21st. Walmart’s option has a 60 day period of expiration, making a Walmart buy a very enticing offer if you have any concern over how much data you might use and whether you’ll be paying too much or too little.

Still no word on if you’ll have to purchase a MBB device with the plan or if you can bring your own. Hopefully we’ll have all those questions answered and more before these new plans launch on May 21st.