Xblue X16 Small Office Phone System 2 Telephone Line Expansion Board (XB1630-00) 2 Telephone line expansion board for the X16 phone system This expansion board adds 2 additional Telephone lines to the system This product is manufactured in China 2 Telephone line expansion board for the X16 phone system. This expansion board adds 2 additional Telephone lines to the system This expansion board will bring the system to its maximum capacity of 6 telephone lines.