A connector comprises a cage, a radiator disposed on a top wall of the cage and having a vertical slot extending through the radiator in a lateral direction of the radiator, a clip adapted to be locked to the top wall of the cage, and a sealing cover mounted on the vertical slot. The clip has an elastic lateral beam received in the vertical slot and adapted to press the radiator on the top wall of the cage. The sealing cover at least partially seals the vertical slot.