PT 57 NG - Loudspeaker terminalLoudspeaker terminal with recessed terminal board and foam sealing for airtight installation. For cable diameters of up to 10 mm2, 2-pole, 1 red and 1 black lever each. more→Round mounting cutout. ncluding mounting screws.DetailsLoudspeaker terminal with recessed terminal board and foam sealing for airtight installation. For cable diameters of up to 10 mm2, 2-pole, 1 red and 1 black lever each. Round mounting cutout. Including mounting screws.