Cup Holder: The retractable base can be adjusted from 6.6 to 9.7 cm in diameter to fit different types of car cup holders. Simply twist the adapter's base to extend or retract the base, and it can be securely fastened in the car's cup holder. U-shaped notch: This design is very practical as cups or mugs with handles can be perfectly placed in this car cup holder without tipping over or spilling. Shrapnel and silicone coaster: The silicone insert in the car cup holder allows cups to be easily inserted and removed from the adapter. The coaster ensures that the cup stays firmly in the cup holder while driving, it will not shake or fall out, and prevents friction against the bottle's body. Durable material: The main body of the car cup holder is made of plastic (ABS), lightweight, durable, waterproof, and easy to clean. Suitable for various sizes: The silicone shrapnel allows the adapter to work with bottles/mugs with a diameter of 7.4 to 9.8 cm. Extended version of the cup body to fit taller and larger mugs, more stable and less prone to shaking, and fits most water bottles from 591 ml to 1134 g.