a body that extends in a first direction and defines a hollow portion therein;

a base that is coupled to the body and defines a communication hole in communication with the hollow portion;

an electric connection part electrically connected to an external power source, the electric connection part extending in the first direction and penetrating through the hollow portion and the communication hole; and

a guide that faces the base and is disposed inside the body, the guide defining a penetrating hole that is in communication with the communication hole and that receives the electric connection part,

wherein the guide comprises a plurality of guide portions spaced apart from one another in the first direction,

wherein the body comprises an engaging protrusion that extends radially inward from an inner circumferential surface of the body toward the electric connection part, the engaging protrusion supporting one of the plurality of the guide portions, wherein an inner diameter of the engaging protrusion is less than a diameter of the hollow portion and greater than a diameter of the penetrating hole,

wherein an inner circumferential surface of the base surrounds the communication hole,

wherein the base includes a support protrusion that extends radially inward from the inner circumferential surface of the base toward the electric connection part, the support protrusion supporting another one of the plurality of guide portions, wherein an inner diameter of the support protrusion is less than or equal to a diameter of the communication hole and greater than the diameter of the penetrating hole,

wherein the engaging protrusion is in direct contact with and supports a lower surface of the one of the plurality of the guide portions, and

wherein the support protrusion is in direct contact with and supports a lower surface of the another one of the plurality of the guide portions.