More than 35,000 Evenflo Sidekick auto booster seats are being recalled because they do not meet federal safety standards, the National Highway Traffic Safety Administration announced Thursday.
The recall involves booster seats with model numbers beginning with 244, manufactured between April 23, 1996, and May 20, 1997, the agency said.
Some 35,856 seats are involved in the recall.
The agency said that when the seats were tested with a dummy they allowed more head damage than permitted under standards for seats for children.
The agency said the danger occurs when the booster seat is used with its shield.
The shield is necessary when the seat is used in a car that has only lap belts.
Evenflo is advising parents to use the seats only without the shield, in cars with both lap and shoulder belts.
Consumers who can continue to use the seats will receive a partial refund and those who must discontinue their use can get a full refund, according to the safety agency.