Here is the safety recall notice from Britax Child Safety, Inc:

Britax Child Safety, Inc. announced that it is conducting a voluntary safety recall on the Frontier™ combination Harness-2-Booster™ child restraints. The recall includes Frontier child restraints manufactured between April 1, 2008 and September 14, 2008 for Model #s E9L54E7, E9L54H6, E9L54H7 and E9L54M6 and between April 1, 2008 and September 17, 2008 on Model # E9L5490.

If the harness straps are repeatedly loosened one strap at a time, then the harness strap(s) may become detached from the metal yoke located on the back of the child seat. If the harness strap(s) becomes loose or detached then the condition can be corrected by inspecting the back of the child seat and reattaching the harness straps. If this condition occurs, the child may not be properly restrained, and in the event of a vehicle crash there could be an increased risk of injury.

To address this issue, Britax will provide two rubber caps that can be easily placed on the yoke slots to prevent the harness straps from detaching. The rubber caps have been specifically designed for the Frontier yoke to provide a secure fit and have been tested to verify their effectiveness.

No later than January 7, 2009, the rubber caps will be mailed with an instruction sheet to all registered Frontier child restraint owners with manufacturing dates prior to September 15 or 18, 2008.

Until consumers receive their remedy kit, they should confirm that their harness system is properly attached to the metal yoke and they may continue to safely use their child restraint.

The location of the label is on the child's right-hand side, near the top of the seat. There should be a white label with the seat's serial number, manufacture date, and batch number.