Apple today announced a voluntary recall and exchange program concerning select first-party AC wall plug adapters and the firm’s World Travel Adapter Kits that include these adapters.

The three-prong adapters designed for use primarily in Hong Kong, Singapore and the United Kingdom are affected. “In very rare cases”, as the Cupertino tech giant put it, these things can break and therefore create a risk of electrical shock if touched.

These wall plug adapters shipped with Mac and certain iOS devices between 2003 and 2010 and were also included in the Apple World Travel Adapter Kit. Apple is aware of six incidents worldwide.

The recall program will exchange affected wall plug adapters with a new adapter, free of charge. Here’s how to identify affected adapters.

Affected three-prong wall plug adapters are white, with no letters in the inside slot where it attaches to an Apple power adapter. New adapters are white with gray on the inside portion that attaches to the power adapter.

Apple provided the following illustration to help identify faulty adapters.

This recall does not affect any Apple USB power adapters.

For details on how to exchange an affected plug adapter, visit apple.com/support.