Google will will start to take online orders on April 15 for the wearable device -- Google Glass, which is only opened to the U.S. public. The price of Glass is $1500 for a limited time.

From next Tuesday on, Google will expand more users in its Explorer program about the Google Glass for limited time and quantity. Google didn't say how many paris it would plan to sell, what it only have already said is "limited quantity".

"We get requests from those persons who can't take part in purchasing Glass everyday, and of course that we want your feedback too. That's why we will be trying to expand the plan of Explorer Program next Tuesday, April 15, and it will become our latest and biggest expansion. Everyone will be allowed to become an Explorer by purchasing Glass in U.S.. " Google said on Thursday blogpost.

Many tech pundits think that wearable devices which included smartphones and headsets will become a fad this year, extending capabilities of smartphone and tablet.

Nevertheless, Google Glass has raised about privacy concerns, and that made some legislators propose bans on these products like Glass.