Jun 14, 2011 13:11 GMT  ·  By

Apple has officially started selling unlocked iPhones through its online store pricing the handset at $649 for the 16GB model, and at $749 for the version with 32GB of storage. Both black and white colored models can be purchased.

Cupertino is enticing potential customers by noting that the unlocked version of the iPhone 4 boasts the same attractive features as the subsidized version, including FaceTime video calling, Retina display, HD video recording, and more.

It advertises the phone saying “you can activate and use on the supported GSM wireless carrier of your choice, such as AT&T in the United States.”

The main benefit of buying the device in the States is the ability to use the handset without restriction overseas.

“If you don’t want a multiyear service contract or if you prefer to use a local carrier when traveling abroad, the unlocked iPhone 4 is the best choice,” Apple adds.

“It arrives without a micro-SIM card, so you’ll need an active micro-SIM card from any supported GSM carrier worldwide.”

A micro-SIM card is a small card used in the iPhone 4 and other cellular devices that stores the wireless account information.

With an unlocked iPhone, users will need to obtain a micro-SIM card directly from their GSM carrier, Apple said.

Global System for Mobile Communications, or GSM, is an industry standard for wireless communication that’s used by most carriers around the world, including AT&T in the United States.

Operators like Verizon use a different technology called CDMA. This version of the iPhone, for example, does not come unlocked.

For those who were hoping to buy the factory-unlocked iPhone in the States and have it shipped abroad, Apple clarifies that “Orders placed through the Apple Online Store can be shipped only within the country of purchase.”