Feature●2 Goldwood Sound PT-308 heavy duty ABS plastic speaker cabinet port tubes●3" diameter per port, 4.5" length per port and 3.875" outside diameter flare●Ports contribute significantly to the low frequency output●Use for speaker cabinet, home speaker or car speaker●This listing and price is for 2 port tubesDescription These Goldwood Sound PT-308 black heavy duty ABS plastic port tubes. Give your cabinets a professional appearance with these attractive port tubes. When properly tuned, the port contributes significantly to the low frequency output of the speaker system.