Cover ornamented with rubber stamps in green ink: circular design with sketch of hand holding a fountain pen at center, and "WRITE - NOT ANSWERING MY MAIL CAN BE HAZARDOUS"; pointing hand with "YOU OPEN CAREFULLY! The use of a knife or blade may damage the luxurious item within." Rubber stamps in black ink: sender's return address, carton hand with "AQUÍ", "POST/ARTE", scissors. US Letter sheet enclosed. Poster for a mail art exhibition organised by Nada Post. Includes typewritten list of participants. "FLUXUS" stenciled in white paint.