What Size Fits: Cup holder works best with bottles/cups 3.35"-3.75" in diameter, fits 32 oz. - 40 oz. water bottles and 40 oz 50/50 Flask. Our cup holder upper cup is 3" high, 3" upper cup will hold your bottles/cups while driving and making turns. Add Foam Sleeve to Protect Your Car: Soft foam sleeve included with cup holder. This sleeve makes sure you get a great fit, use this soft foam sleeve, your vehicle's cup holders will be protected from scratches and damage. U Shaped Cut Out Design: Incorporates 1" U shape cut out to accommodate coffee cups or travel mugs with external handles that will fit perfectly. Cup holder works in cars, trucks, RVs, boats, golf carts. Unbreakable Material: Made from high strength ABS plastic with a glossy finish. Unbreakable in extreme heat or cold. Perfect Companion: Cup holder adapter for large cups provides stress-free driving since there is no rattling, and the drink is securely held. Match cup holder with your car and enjoy pleasant journey. What Size Fits: Cup holder works best with bottles/cups 3.35"-3.75" in diameter, fits 32 oz. - 40 oz. water bottles and 40 oz 50/50 Flask. Our cup holder upper cup is 3" high, 3" upper cup will hold your bottles/cups while driving and making turns. Add Foam Sleeve to Protect Your Car: Soft foam sleeve included with cup holder. This sleeve makes sure you get a great fit, use this soft foam sleeve, your vehicle's cup holders will be protected from scratches and damage. U Shaped Cut Out Design: Incorporates 1" U shape cut out to accommodate coffee cups or travel mugs with external handles that will fit perfectly. Cup holder works in cars, trucks, RVs, boats, golf carts. Unbreakable Material: Made from high strength ABS plastic with a glossy finish. Unbreakable in extreme heat or cold. Perfect Companion: Cup holder adapter for large cups provides stress-free driving since there is no rattling, and the drink is securely held. Match cup holder with your car and enjoy pleasant journey.