T-Mobile has officially started allowing customers to pre-register for the LG G Flex curved display smartphone.

The LG G Flex is the world's first curved-display smartphone to make it to the U.S. LG announced the handset's U.S. availability at CES 2014, and Sprint was the first carrier to open up pre-orders for the device a few days ago.

While Sprint has already started taking pre-orders for the handset for $299.99 on-contract, T-Mobile only opened up pre-registration. This means that the UNcarrier is not yet taking pre-orders, and has not offered any pricing details for now.

The LG G Flex is a high-end smartphone with impressive specs and features. The handset sports a 6-inch curved P-OLED display with a resolution of 1280 x 720 and a pixel density of 245 pixels per inch (ppi). It packs a 2.26GHz Qualcomm Snapdragon 800 quad-core processor, Adreno 330 graphics, and 2GB of RAM.

Other specs of the LG G Flex include 32GB of internal storage capacity, but with no microSD card slot for additional storage. The smartphone further features a 13-megapixel rear camera with auto focus, LED flash, and full HD 1080p video recording capabilities, and a 2.1-megapixel front camera. In terms of connectivity, the LG G Flex supports 4G LTE, Wi-Fi 802.11 a/b/g/n/ac, Bluetooth 4.0 LE, GPS, and NFC. The smartphone comes with a 3,500 mAh non-removable battery that will provide up to 29 hours of talk time, and ships with Android 4.2.2 Jelly Bean on board.

Aside from the impressive specifications and the curved display, the LG G Flex also comes with another cool feature: a self-healing back plate that automatically recovers from the minor scuffs and scratches of everyday wear and tear.

T-Mobile has yet to announce just when it will start taking pre-orders or actually selling the LG G Flex, and for how much. For now, the carrier is just offering pre-registration, which means that you can leave your name and email address in order to be notified as soon as more information becomes available. Head here to pre-register your interest in the T-Mobile LG G Flex. Pre-registration entails no obligations, meaning that if you pre-register your interest you are not committing to actually purchasing the handset.