A plug comprising a plug body, • wherein a first row of slots and a second row of slots are disposed on the plug body, and the first row and the second row are parallel; and the plug further comprises first pins in one-to-one correspondence with the first row of slots and second pins in one-to-one correspondence with the second row of slots; wherein • the first pin comprises: ∘ a first straight portion, a second straight portion, and a bent portion, wherein the bent portion connects the first straight portion to the second straight portion, so that the first pin is L-shaped, ∘ wherein the first straight portion of the first pin is embedded in a slot, in a corresponding position, of the first row of slots, and the second straight portion is configured to connect to a first printed circuit board, PCB,; and • the second pin comprising: ∘ a first straight portion, a second straight portion, a third straight portion, a fourth straight portion, a first bent portion, a second bent portion and a third bent portion, wherein the first bent portion connects the first straight portion to the second straight portion, the second bent portion connects the second straight portion to the third straight portion and the third bent portion connects the third straight portion to the fourth straight portion, so that the second pin is stair-shaped, ∘ wherein the first straight portion of the second pin is embedded in a slot, in a corresponding position, of the second row of slots, and the fourth straight portion of the second pin is configured to connect to the first PCB and is parallel to the second straight portion of the first pin, wherein the second straight portion of the first pin has an inner side facing the plug body and an outer side facing away from the plug body characterized in that the fourth straight portion of the second pin has an inner side facing the outer side of the second straight portion of the first pin and an outer side facing away from the plug body. • wherein a first row of slots and a second row of slots are disposed on the plug body, and the first row and the second row are parallel; and the plug further comprises first pins in one-to-one correspondence with the first row of slots and second pins in one-to-one correspondence with the second row of slots; wherein • the first pin comprises: ∘ a first straight portion, a second straight portion, and a bent portion, wherein the bent portion connects the first straight portion to the second straight portion, so that the first pin is L-shaped, ∘ wherein the first straight portion of the first pin is embedded in a slot, in a corresponding position, of the first row of slots, and the second straight portion is configured to connect to a first printed circuit board, PCB,; and ∘ a first straight portion, a second straight portion, and a bent portion, wherein the bent portion connects the first straight portion to the second straight portion, so that the first pin is L-shaped, ∘ wherein the first straight portion of the first pin is embedded in a slot, in a corresponding position, of the first row of slots, and the second straight portion is configured to connect to a first printed circuit board, PCB,; and • the second pin comprising: ∘ a first straight portion, a second straight portion, a third straight portion, a fourth straight portion, a first bent portion, a second bent portion and a third bent portion, wherein the first bent portion connects the first straight portion to the second straight portion, the second bent portion connects the second straight portion to the third straight portion and the third bent portion connects the third straight portion to the fourth straight portion, so that the second pin is stair-shaped, ∘ wherein the first straight portion of the second pin is embedded in a slot, in a corresponding position, of the second row of slots, and the fourth straight portion of the second pin is configured to connect to the first PCB and is parallel to the second straight portion of the first pin, wherein the second straight portion of the first pin has an inner side facing the plug body and an outer side facing away from the plug body characterized in that the fourth straight portion of the second pin has an inner side facing the outer side of the second straight portion of the first pin and an outer side facing away from the plug body. ∘ a first straight portion, a second straight portion, a third straight portion, a fourth straight portion, a first bent portion, a second bent portion and a third bent portion, wherein the first bent portion connects the first straight portion to the second straight portion, the second bent portion connects the second straight portion to the third straight portion and the third bent portion connects the third straight portion to the fourth straight portion, so that the second pin is stair-shaped, ∘ wherein the first straight portion of the second pin is embedded in a slot, in a corresponding position, of the second row of slots, and