1. 2. A tuned port designed for bass drum 3. Extend your low-end frequencies 4. Add more punch to your sound 5. Make the bass part more powerful, and the effect is adjustable; You only need to adjust the tightness of the drum surface Enhancer instantly improves the sound of any bass drum High wear-resistant and excellent durability Usage Method: First put the protective sticker on the kick drum skin, and cut along the inner diameter circle to make a complete circle. The rubber part of the speaker is stuck on the drum skin and the installation is complete Color: White Material: ABS + Rubber Size: Outer diameter: 18.5cm Inner diameter: 10.6cm / 4.17 inch Height: 10.5cm / 4.13 inch Weight: 190g / 6.7oz Package Contents: 1 x Bass drum enhancer 1 x Protection sticker Only the above package content, other products are not included Note: Light shooting and different displays may cause the color of the item in the picture to be slightly different from the real thing. The measurement allowed error is +/- 1-3cm