Plug, receptacle, and connector

A plug for mating with a receptacle, the plug comprising:

• an insulator that has an inner bottom surface, the inner bottom surface being orthogonal to a mating direction of the plug;
• and
• a plurality of pin contacts secured to the insulator and aligned in an alignment direction, each of which includes a contact tab having a pair of planar surfaces of the contact tab on two mutually opposite sides thereof which are parallel to each other, the planar surfaces of the contact tab each forming a contact surface;
• wherein the contact tabs stand up from the inner bottom surface in the mating direction, the contact surfaces being parallel to the alignment direction;
• wherein a plurality of protrusions are formed in the insulator that stand up from the inner bottom surface in the mating direction, such that each of the protrusions is positioned between two of the contact tabs which are next to each other in the alignment direction;
• wherein a projecting strip having a trapezoidal section and extending in the mating direction is formed on a lateral surface of the contact tab which faces the alignment direction, the lateral surface of the contact tab being opposed to a lateral surface of the protrusion adjacent to the contact tab in the alignment direction;
• and
• a groove having a trapezoidal section and extending in the mating direction is formed on the lateral surface of the protrusion, wherein the projecting strip is fitted into the groove.