A travelling belt for a baby cradle in a car—often called a "CarNap" or car hammock strap—is designed to securely suspend a portable cradle or hammock inside a vehicle. These systems typically use heavy-duty nylon straps and adjustable buckles to attach to the car's grab handles or overhead supports, providing a gentle swinging motion for the baby during travel. 

• Adjustable Belt System: Most kits include a long overhead strap (often up to 2.1 metres) and a pair of shorter handle straps that attach to the car's grab handles.
• Universal Fit: The adjustable nature of these belts allows them to fit in various car types, including sedans, hatchbacks, and SUVs.
• Material and Strength: Straps are commonly made of reinforced nylon webbing (about 38 mm wide and 2.5 mm thick) to distribute weight evenly and maintain stable suspension.
• Anti-Slip Buckles: These ensure a firm grip and prevent the straps from loosening while the vehicle is in motion.
• Portability: The systems are lightweight and foldable, often coming with a handy carry pouch for travel. 
  Usage and Safety Considerations
• Installation: Typically involves wrapping the buckles around car handles and securing metal hangers to support the hammock cloth
• Age and Weight Limits: Most are recommended for babies aged 0 to 3 years or up to a maximum weight of 15–20 kg.
• Comfort: Designed to minimize jerks and reduce the chances of nausea or vomiting during long journeys.