The U.S. Consumer Product Safety Commission (CPSC) is warning consumers to immediately stop using Cyclingsell Zacro adult bike helmets because they can fail to protect a cyclist’s head in the event of a crash.

The seller, cyclingsell.com, of China, has not agreed to recall the helmets or to offer a remedy to consumers who purchased the equipment. CPSC said the helmets do not comply with the positional stability, labeling and certification requirements of the mandatory federal safety standard for bike helmets.

The Zacro bicycle helmets were sold online at cyclingsell.com from April 2022 through July 2023 for about $50.

The Chinese company sold the helmets in large and extra-large, fitting a head circumference of about 22 to 24 inches. The helmets are white with black accents, a black and gray strap, a red and black buckle, and an adjustable spin dial on the back.

CPSC encourages consumers to report incidents involving product injuries or defects to CPSC at SaferProducts.gov.