Area Code 312
Local Presence for Chicago, Wheeling, and Northbrook
You can increase your connection rate up to 30% by dialing from a local number.
Local Presence by Tenfold gives you one-click access from your existing phone system to a local number in the US area code 312 and more than 200 others.
Reach out to customers in Chicago, Wheeling, and Northbrook.
Source: Wikipedia