Poland - power plug and socketIn Poland , electrical sockets and plugs are type C or E.
Type C has two round pins and type E has two round pins and a hole for the socket's male earthing pin.
Check the markings on the device before traveling. Each electrical device has a label (often on the charger) stating at which volt range and frequency it works - example “INPUT: 100-240V, 50/60 Hz”. If this range is also in the target country, you do not need a voltage converter, just check the type of socket / plug. More information about the voltage converter can be found here. Many modern hotels are equipped with several types of electrical outlets. If you already have a selected hotel where you will be staying, call there and ask about the types of electrical outlets. If you have not choosed a hotel yet, you can check them out on (Accommodation - booking.com)