- Adjustable Fit for Multiple Vehicles: This cup holder insert expands from 2.8" to 3.9", making it compatible with a wide range of vehicles including Tesla models, RVs, trucks, SUVs, treadmills, and golf carts. It's the ideal solution for anyone needing extra drink space on the go. - Robust Design for Larger Bottles: Designed to securely hold bottles ranging from 10 oz to 40 oz, this cup holder expander stabilizes your favorite beverages. It accommodates bottle diameters from 2.4 inches to 4 inches, effectively preventing spills and tipping while driving. - 2-in-1 Functionality: This versatile cup holder not only holds your drinks but also features a dedicated phone holder. Keep your device secure and accessible while driving, compatible with most smartphones including the iPhone 15 Pro Max and Mini. - Durable and Reliable Materials: Constructed from high-quality, shockproof materials, this cup holder expander provides a stable and safe support system for your drinks and phone. Its secure grip technology ensures peace of mind during your travels, whether you are listening to music or using navigation. - Practical Use Cases: Perfect for road trips where beverage organization is essential, daily commutes where phone accessibility is needed, or for athletic activities like golfing or using a treadmill, ensuring you stay hydrated and connected. This cup holder expander is a must-have accessory that enhances convenience and safety in any vehicle.