Shipping time depends on various factors such as postal service efficiency, customs clearance, international transit, etc., which is why we give you an approximation based on our statistics and former experience.
Usually 80-85% of airmail packages arrive with 10 days, and 15-20% arrive within 10-15 business days. This is a reflection of inconsistencies with various postal representatives, and not services provided by us. The main delay happens due to custom clearance in country where the products are being sent from and custom in destination country. In case you see that your tracking code does not move during 5 days this is the main reason why this happens.
Every international shipment normally passes through the local and national postal service in the country of origin, then exportation, as well as shipment transfer through ports of exit, transit to destination country with international postal service, importation in destination country (customs clearance), and finally the local and national postal service in the destination country. Each successive step has an impact on the delivery time. Even if the majority of these steps are successfully executed in a timely manner, inefficiency or temporary inactivity during any single step is enough to extend delivery time over the usual and allotted time frame.