Features: It can increase the volume of the without increasing the power of the speaker itself.. Perfectly replaces your old and broken sound guide tube, increase the volume, and improve the efficiency of the speaker.. Standard mount holes make this tube easier and convenient to install than others on the market. You can experience good looks, low distortion, and superior overall sound quality.. brand new and high quality Special curved inverting tube for sound box, suitable for sound box, ABS plastic material.. Specifications: Item: Special Inverting Tube for Sound Box Size: S/for M/L Open Hole Diamater : approx S: 50mm/1.97in M: 64mm/2.52in L:79mm/3.11in Length approx : S 98mm/3.86in M:125mm/4.92in L:176mm/6.93in Small approx 50mm: for 5inch 6.5inch Speaker Medium approx 64mm: For 6.5inch 8inch Speaker Large approx 79mm: For 8inch 10inch Speaker Quantity: 1PC Package Includes: 1 PC x Curved Speaker Port Tube (Without Speaker) note: Due to the lighting effects and shooting angles, there is color difference in the product, please understand. Due to manual measurement, there is a tolerance in the product size.