Quality Park 46010 White Kraft Mailing Tubes w/Recessed End Plugs, Inside: 36 x2 Dia, 25/ctn White Mailing Tubes. Fiberboard tubes covered with white Kraft. Recessed plastic end plugs (included) secure contents, give tubes extra rigidity. Fiberboard tubes covered with white Kraft. Recessed plastic end plugs (included) secure contents, give tubes extra rigidity.