A jack capable of handling both Category 6 and Category 7 speed communications. The jack includes a shield, a housing disposed in the shield and a contact block disposed in the housing. The contact block includes a base member and a plurality of contacts carried by the base member. Each contact includes a contact portion effective to touch a corresponding contact of a plug when the plug is inserted into the jack, a first end portion effective to be inserted into a circuit board, and a second end portion. A flexible substrate is connected to the second end portion, the substrate including a compensation circuit for the jack.