Signal with confidence: The Lumos signal holder enhances your visibility with clear signals and ensures your safety by mimicking the recognized distances of car taillights. Suitable for every rider: This holder is universally compatible with standard saddle rails with a diameter of 7-10 mm and a spacing of 45-75 mm, ensuring a perfect fit for a variety of bicycles. Sturdy and reliable: Made from a high-quality aluminum alloy, the signal holder has undergone rigorous testing to withstand the elements and daily wear and tear while cycling. Effortless setup: The signal holder comes with comprehensive instructions and all necessary tools for a hassle-free installation, so you can get back on the road in no time. Customize your visibility: With the ability to easily adjust the angle of your Firefly lights, the holder ensures that you are visible from all directions on every ride.