Hong Kong and Macao Travel Permit

The Hong Kong and Macao Travel Permit (alternatively known as the Exit-Entry Permit for Travelling to and from Hong Kong and Macao; colloquially as Two-way Permit or EEP) is a travel document issued by the Exit and Entry Administration of the People's Republic of China. This card-size biometric document is issued to Chinese citizens residing in the mainland for traveling to and returning from Hong Kong and Macau for personal purposes.

Source: Wikipedia — Hong Kong and Macao Travel Permit (CC BY-SA 4.0)