Speaker poles typically have a standard diameter of 35mm (about 1.38 inches), which is a common size designed to fit into the corresponding pole mounts on most PA speakers and subwoofers. This standardisation ensures compatibility across a wide range of brands and models, allowing for easy integration of speakers with stands or subwoofers. Some speaker systems or stands may offer different diameters or adjustable options, but 35mm remains the predominant size for universal speaker pole fittings.