Four speaker cabinet adapters are in the package, two with 35mm (1 3/8) pole mounting, two with M20 threaded mounting. Mounting screws are included Adapters with 35mm (1 3/8') mounting add pole-mount sockets to speakers, enabling use with speaker stands and brackets Adapters with M20 threaded mounting replace the standard pole-mount sockets on top of subwoofers, ensuring a stable connection between a subwoofer and a speaker pole Crafted with durable iron (35mm) and aluminum (M20) for lasting quality