Electrical connector and combination connector having the same

An electrical connector to be attached to a circuit board, comprising:

• a housing having a first sidewall surface and a second sidewall surface, said first sidewall surface extending in a first direction in parallel to the second sidewall surface with a first distance therebetween;
• a first terminal disposed on the housing, said first terminal having a first contact portion protruding from the first sidewall surface in a second direction substantially perpendicular to the first direction;
• a second terminal disposed on the housing, said second terminal having a second contact portion protruding from the second sidewall surface in the second direction;
• and
• an extension portion having a first external wall surface and a second external wall surface, said extension portion being arranged so that a center point between the first external wall surface and the second external wall surface in the second direction is shifted with respect to a center point between the first contact portion and the second contact portion in the second direction, said first external wall surface extending in the first direction in parallel to the second external wall surface with a second distance therebetween larger than the first distance.