Bass drum enhancer is a good helper for improving the sound of a bass drum. It's made of high-quality material and is easy to use. Features: This is a tuned port designed for bass drums. Easy to install and use. Lowers the tone of the bass drum and adds more punch to the sound. Makes the bass part more powerful, and it's easy for you to adjust the effect by just adjusting the tightness of the drum surface. The enhancer is helpful in improving the sound of a bass drum. Made of good-quality ABS and rubber material, with high strength and great durability. Note: Size and color may be slightly different due to manual measurement and different light conditions. Thanks for understanding. Using 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 loudspeaker is stuck on the drum skin and the installation is complete. Specifications: Color: White/ Red/ Black (Optional) Material: ABS + Rubber Inner Diameter: 10.6cm / 4.17in Outer diameter: 18.5cm / 7.28in Height: 10.5cm / 4.13in Package Size: 19 * 19 * 11cm / 7.48 * 7.48 * 4.33in Package Weight: 190g / 6.70oz Package List: 1 * Bass Drum Enhancer 1 * Protection Sticker