While Samsung's Galaxy S4 is gearing up to hit the global shelves, the much-rumored dual-SIM variant of the smartphone has been officially unveiled, albeit in China. The dual-SIM version is called Samsung Galaxy S4 Duos and has gone on sale in China under the Samsung I9502 model number.

Apart from the inclusion of two SIM card slots in the just-released Galaxy S4 Duos, the smartphone is identical to the Samsung 2013 flagship Galaxy S4, which was announced on March 14 at an event in New York.

"We've known that there will be a dual-SIM version of the Samsung Galaxy S4 since before the smartphone was even official. Now Samsung has officially unveiled the I9502 Galaxy S4 with two SIM slots," reports GSM Arena.

Like the Galaxy S4, the Galaxy S4 Duos sports the same 5-inch 1080p full HD Super AMOLED screen. The smartphone is powered by the Exynos 5 Octa-Core processor which is clocked at 1.6GHz and not the Snapdragon 600 one.

The smartphone also touts a 13-megapixel rear-facing camera (with 1080p videos at 30fps) and a 2.1-megapixel secondary snapper.  The device has 2GB of RAM and boasts PowerVR SGX 544MP3 graphics.

The Galaxy S4 Duos also comes pre-loaded with Android 4.2.2 Jelly Bean with Samsung's new TouchWiz UX 2.0 running on top. The dual-SIM smartphone also packs in the new Smart Pause and Smart Scroll features, Air View, Festure View, Smart Stay, S Voice, S Health and S Translator.

Samsung has also launched another Galaxy S4 model, I9406, which is single-SIM China-bound one and runs on the Snapdragon 600 processor and has TD-SCDMA 3G connectivity.

"There's another Chinese model, the I9508, which is a single-SIM Galaxy S4 with a Snapdragon 600 chipset. This one is China-specific and differs from the I9505 in its TD-SCDMA support (the 3G tech in China)," notes GSM Arena.

It is not yet known if the Galaxy S4 Duos will release globally or remain confined to Chinese shores.