Fields Laboratories holds a valuable patent (No. 758-6002-1A) on a precipitator that prevents certain types of air pollution. Fields does not manufacture or sell the products and processes it develops. Instead, it,conducts research and develops products and processes that it patents, and then assigns the patents to mariufacturers on a royalty basis. Occasionally it sells one of its patents. The history of Fields patent number 75860021A is as follows. Fields assumed a useful life of 17 years when it received the initial precipitator patent. On January 1, 2016, it revised its useful life estimate downward to five remaining years. The company's year ends December 31 . Fields 14 follows IFRS for reporting purposes. Fields Laboratories holds a valuable patent (No. 758-6002-1A) on a precipitator that prevents certain types of air pollution. Fields does not manufacture or sell the products and processes it develops. Instead, it,conducts research and develops products and processes that it patents, and then assigns the patents to mariufacturers on a royalty basis. Occasionally it sells one of its patents. The history of Fields patent number 75860021A is as follows. Fields assumed a useful life of 17 years when it received the initial precipitator patent. On January 1, 2016, it revised its useful life estimate downward to five remaining years. The company's year ends December 31 . Fields 14 follows IFRS for reporting purposes