According to the Airofog Puffer Duster Manual: Airofog USA guarantees the Puff Duster to be free of defects in materials and workmanship to the original purchaser for a period of one(1) year on labor and parts which are not subject to usual wear. During this period, AIROFOG USA will replace and/or repair the parts and manufacturer faults on the exclusive judgment of our technical department free of charge. Shipping and dispatch of defect equipment will be at original purchaser's expense. Guarantee does not cover damages occurred during transport or by incorrect handling, tampering, use, or the use of non-recommended products and so on. Under no circumstances will AIROFOG USA be liable for damages due to improper use or application. Under no circumstances will AIROFOG USA be responsible for damages to any persons or property.