E-commerce giant Amazon issued a voluntary recall Wednesday on several of its AmazonBasics-branded portable charging power banks, citing concerns over the devices overheating and melting and starting fires.

The recall will be carried out in cooperation with the Consumer Product Safety Commission (CPSC) and will be focused on six models of Amazon’s house-brand power banks sold over a nearly three-year period.

The Verge reported the recall will affect six models of AmazonBasics Portable Power Banks sold between December 2014 and July 2017.

According to a recall email sent by Amazon to owners of the recalled devices, the affected models include the following make and model number:

  • AmazonBasics Power Bank (16,100 mAh battery), Product Number B00ZQ4JQAA

  • AmazonBasics Power Bank (10,000 mAh battery), Product Number B00LRK8JDC

  • AmazonBasics Power Bank (5,600 mAh battery), Product Number B00LRK8IV0

  • AmazonBasics Power Bank (3,000 mAh battery), Product Number B00LRK8170

  • AmazonBasics Power Bank with MicroUSB Cable (2,000 mAh battery) Product Number B00LRK8EVO

  • AmazonBasics Power Bank with MicroUSB Cable (3,000 mAh battery), Product Number B00LRK8HJ8

The power banks were manufactured for Amazon to be sold under the AmazonBasics label by Guoguang Electric Company, an electronics manufacturer based in China.

Amazon has removed all of the affected models from its store to prevent more from entering circulation. The potentially dangerous models of the AmazonBasics Power Banks can no longer be purchased.

According to the email from Amazon, consumers who have purchased the affected devices are advised to unplug them immediately and stop using the product, then register the device with Amazon to receive instructions on how to return it as part of the recall. The company is promising to provide customers with refunds for their purchases.

A report from the CPSC indicated that Amazon has received 53 reports of its power banks overheating, including one report of chemical burns caused by contact with battery acid and four reports of property damage, including fire and smoke damage.

“The safety and satisfaction of our customers is our highest priority,” Amazon said in the email. “We regret any inconvenience this may cause you.”