Tether booster seat
Choosing the right child restraint affects how a booster seat controls upper-body movement during a crash. A tether booster seat uses a top tether strap that connects the upper part of the restraint to a vehicle anchor, reducing forward head excursion and rotation. This overview explains what the tether does, how that changes restraint installation, and when the feature matters compared with a belt-positioning booster without an upper anchor. The discussion covers typical harness fit and seat belt routing considerations without treating any single vehicle or seat as universal.
Essential answer
A tether booster seat combines a booster’s seated-position function with an upper tether connection. In a conventional high-back booster, the lap-and-shoulder belt positions the child, while the seat itself does not usually carry upper tether loads. When a booster includes a tether, the additional strap anchors the seat’s shell or an attached harness system to the vehicle. That anchoring reduces how far the top of the restraint can move forward in a frontal impact, improving upper-body control when the design requires or permits it.
The scope depends on restraint type. Some child restraints marketed as combination or harness-capable seats use an internal five-point harness and require a top tether above a weight threshold. A backless booster is not typically tethered because it relies entirely on the vehicle belt for positioning. The upper tether does not replace lower anchors or seat belt routing; it works with a properly installed restraint. Vehicle-specific confirmation is necessary because anchor locations, weight limits, and manufacturer instructions differ between models and child-restraint designs.