Apple has announced a recall of wall plug adapters used in the UK, Hong Kong, and Singapore. It follows six incidents of electric shocks resulting from the plugs breaking, exposing metal contacts.

The plugs were sold with a range of Macs, iPhones, iPads and iPods, but you only have to worry about them if you’re using a rather elderly model – or bought the official Apple World Travel Adapter Kit a long time ago …

In addition to the three primary countries listed, the plug adapters may also have been supplied in mainland Europe, Australia, New Zealand, Korea, Argentina, and Brazil.

Apple says that although the recall is voluntary, it would like customers to stop using the existing plugs.

The company is directing affected customers to a support page for its recall of the wall plug adapters. It says that customers will need their Mac, iPad, iPhone, or iPod serial number in order to confirm that they have one of the affected devices, and will then be able to exchange the plugs via online support, an Apple Store, or an Authorized Apple Service Provider.

An affected three-prong plug adapter is white, with no letters on the inside slot where it attaches to the main Apple power adapter. See website for more details and images to identify an affected adapter.