[DESIGNED FOR WALL USAGE] Especially effective for wall-mounted speakers, they help eliminate excessive boominess when space is limited. [LONG-LASTING FOAM MATERIAL] Constructed from open cell type foam, these speaker bungs are built to withstand regular use while enhancing audio performance. [SIZING GUIDELINES] For the fit, select a bung slightly larger than your speaker port diameter; this allows for adjustments as needed. [TWO BUNGS INCLUDED] Each package comes with 2 foam loudspeaker port bungs available in various sizes (35/44/55/60/65mm Diameter x 50/65/50/60mm Height) for applications.