Por transporte aéreo: até 10000 € e não mais pesado que 50 kg. Eu acho que o anel de noivado passaria esses critérios.
The goods for private use except transport vehicles imported on customs territory of customs union in accompanied or unaccompanied luggage
- Goods for private use (except ethanol and the indivisible goods) transported by air transport:
customs cost of which does not exceed the sum equivalent of 10 000 euros and gross weight of which does not exceed 50 kgs