Unregistered mail:
This shipping method is intend for customers
who don`t want to sign for their packages
This is the cheapest shipping method. With this service you only pay for the shipment
seedshop.nl don`t recommend this shipping method

Registered (signed for): 
This shipping method has the same shipping time as 'unregistered shipping'
Registered shipping cost a little bit more.
But because you have to sign for your package the chance for a good arrival will be beter