Abstract: A padlock-type security seal including a U-shaped shackle having a pair of reversely bend end portions. A body portion and a brightly colored insert are assembled to form a pair of chambers for receiving and locking the bent end portions. Movable tangs and matching cavities are formed as an integral part of the insert adjacent the chambers. The body portion has a plurality of transparent windows adjacent the cavities. Attempts to open the seal by deforming the shackle to remove the bent end portions from the chambers will result in moving the tangs into locking containment with the cavities thereby visually indicating tampering via the transparent windows.