EU members are not expected to pay any duties or taxes fee. The rest may be a subject to import duties and taxes, which are levied once a shipment reaches your country.
This is not relevant for the EU, JP, AU, SG and US.
The United Kingdom has now left the EU, therefore, the package can be subject to customs. However, that is not relevant to orders having up to 3 items; including straps. In case you add more watches and straps, unfortunately, your order may be a subject to customs.
The general amount may vary depending on the country to which the order was shipped. You should contact your customs office in order to find out the specific percentages. Nordgreen cannot control and is not responsible for any duties applied to your package.
You will be one responsible for paying any additional charges for customs clearance.