Hong Kong → Cook Islands
Hong Kong plugs
Type GCook Islands plugs
Type INo shared plug types. A travel adapter is required.
Compatibility: Adapter Required
Voltage — Hong Kong 220V — Cook Islands 240V
Voltage difference is small. Most electronics will work safely.
Device compatibility (phones)
Phones almost always support 100–240V, so yours should work safely. Check your charger label to confirm.
You likely only need a plug adapter (if socket shapes differ). Voltage is close between these countries.