A faulty battery that poses an explosion hazard is behind the recall of ION Audio portable speakers, according to the U.S. Consumer Product Safety Commission. Hydrogen gas can leak from the portable speaker battery when charging and the speaker can burst. While there have been five reports of speakers exploding, including four incidents resulting in property damage to the surrounding area, no injuries have been reported, officials said.

“Consumers should immediately stop using the recalled portable speakers and contact ION Audio for a refund in the form of an ION Audio gift card,” the CPSC said in a statement. Call ION Audio toll-free at 833-682-0371 from 8:30 a.m. to 6:30 p.m. ET Monday through Friday or go online to www.ionaudio.com.

Manufactured in China, approximately 41,000 of the Sport Express speakers were sold exclusively at Best Buy from June 2018 through May 2019 for about $70. The Cornerstone, Cornerstone Glow and Keystone speakers were sold at various electronics stores nationwide and online from March 2016 through March 2019. Cornerstone and Cornerstone Glow sold for about $100 and the Keystone sold for about $200. Cumberland, RI-based ION Audio imported the speakers.

The Sport Express speaker is black in color and has two knobs on the front with a neon blue lit clock. It is about 9 inches wide and 9 inches tall. The Cornerstone and Cornerstone Glow speakers are triangular in shape, have a white outer casing and are 14 inches wide and 10 inches tall. The Keystone speaker is square with a white casing and gray center. It is about 8 inches wide and 9 inches tall. The UPC number is located on the bottom of the speakers. To see all the recalled speakers styles, go here.