Antitheft device for commodity items

An antitheft device designed to be attached to an off-the-shelf commodity item, preferably a piece of clothing, in particular in close proximity to the edge of the item, comprising

• a first fastening part, provided with a nail-type pinning element;
• a second attachment part, comprising a hole capable of receiving the said pinning element;
• a locking system designed to retain the pinning element in the said hole, the two parts being connected to one another so as to be movable relative to one another when the pinning element is outside the hole;
• and
• a spring providing the elastic mobility of the fastening part in relation to the attachment part,
• wherein said device comprises an electronic theft detection system, said electronic theft detection system being accommodated in the attachment part and
• wherein the hole has a flared opening and a generally funnel shape, the flared opening being operable to guide the pinning element into the hole during attachment.