This is the best option for children with behavioral issues that won't stay put. There is also a similar model for children who have to lie down. Some families use this system when their child is in long leg casts. Tether Straps Many child restraints designed for children with special health care needs must be installed with a tether strap and a seat belt. A tether strap attaches to the restraint and is bolted into the car to prevent the movement of the car seat in the vehicle.
Some cars come with holes already drilled for tethers.
Others need to have holes drilled for installation. If a family's car seat requires a tether, it is best to take the vehicle to a dealer who can help find the hole or drill one. Never drill a hole independently, as it could puncture the gas line or damage the vehicle. It's about to become much easier to use tethers. The new system will greatly simplify child safety seat installation and will protect children by keeping seats more secure in vehicles.