The Lumia 640 and 640 XL, Microsoft's latest Windows phone releases, will be for the AT&T customers' taking this month. The smaller variant will be available by next week while the bigger one will be available at the end of the month.

While T-Mobile is already set to fill its shelves with the Lumia 640 on June 17, AT&T is the first to put the Windows phone's big brother on offer in the U.S. The device is "coming soon," as listed in the carrier's website. However, Win Super Site assures buyers that it will arrive before the month of June winds to a close. 

Cricket Wireless, which was ahead of the two carriers to offer the standard mid-ranger, has the unlocked version of the device on sale for $129.99. The Lumia 640 is expected to cost around $100 to $150 and the Lumia 640 XL around $200 to $250 when it lands on AT&T. This price range is an estimate and consumers can expect that it will change depending on the two-year contract, promotions, and other rate plans and tie-ups that the respective carriers will put up for the pair of Windows phones. 

The Microsoft Lumia 640 comes with a 5-inch IPS LCD display with a decent 720 pixel resolution. The sizeable XL version measures a massive 5.7 inches but has the same pixel resolution. Their screens are protected with Corning Gorilla Glass 3. 

Both handsets are equipped with a quad-core Qualcomm Snapdragon 400 processor clocked at 1.2 GHz. They both have 8 GB expandable storage and 1 GB RAM. There's Windows 8.1 ready to go, and the 640 and 640 XL have 2500 mAh and 3000 mAh battery units, respectively.

The smaller of the two has an 8-megapixel (with LED flash) and a 1-megapixel camera combo while the bigger one has a 16-megapixel shooter on the front (capable of HD video recording) and a 5-megapixel selfie snapper.

A specific release date has yet to be determined.