ENHANCED DURABILITY - Constructed from robust aluminum and polycarbonate, this speedring insert ensures long-lasting performance and withstands frequent use in demanding environments. SEAMLESS COMPATIBILITY - Designed for Bowens flash mounts and Glow EZ Lock systems, this 139mm speedring insert offers broad compatibility with various lighting setups. SIMPLE AND EASY TO USE - The low-profile design allows for quick and effortless mounting, saving valuable time during photoshoots and ensuring a smooth workflow. SECURE AND STABLE FIT - Provides a reliable and wobble-free connection between your light source and modifier, ensuring consistent and precise light shaping for optimal results.