Fast food giant McDonald’s has recalled children’s activity wristbands, due to the risk of skin irritation or burns. About 29 million wristbands were made for U.S. and 3.6 million for Canada, according to the U.S. Consumer Product Safety Commission (CPSC). They were being distributed in Happy Meals between Aug. 9 and Aug. 17, but after receiving more than 70 reports of incidents, including seven reports of blisters, McDonald’s halted the initiative and issued a recall.

Manufactured in China, the “Step-iT” activity bands come in two styles, an “Activity Counter” and a motion-activated “Light-up Band.” The activity counter comes in orange, blue or green and features a digital screen to track a child’s steps or other movement. The light-up band comes in red, purple or orange, and blinks either rapidly or slowly, depending on a child’s activity level. Both styles have a square face with the words “STEP-iT” printed on them and a button to depress and activate the band. “Made for McDonald’s” is etched on the back. The toys, meant to encourage a healthier lifestyle, were launched to coincide with the Olympic Games in Rio de Janeiro.

According to McDonald’s, many of the roughly 33 million wristbands manufactured were never given to customers, due to the limited distribution dates and its decision to stop distributing on Aug. 17. “Nothing is more important to us than the safety and well-being of our customers, which is why upon learning about concerns with these bands, we acted swiftly to stop distribution of these products,” McDonald’s spokeswoman Terri Hickey said in a press statement.

Consumers should immediately take the recalled wristbands from children and return them to any McDonald’s for a free replacement toy and either a yogurt tube or bag of apple slices, according to the CPSC. More information on the recall is available by calling McDonald’s at 800-244-6227 or visiting www.mcdonalds.com and clicking on “Safety Recall.”