In ruling N314212 (Sept. 17, 2020), Customs and Border Protection (CBP) discussed the classification of an Electrostatic Backpack Sprayer. The backpack sprayer consists of a trigger-activated spray gun, a 2.25-gallon fluid tank designed to be worn on the back of the user, two lithium-ion batteries, a battery charger, and a telescopic wand. The Electrostatic Backpack Sprayer is described as a disinfectant appliance designed for use in industries such as healthcare, facility management, education, etc. As described, the user will squeeze the hand-operated trigger, which draws disinfectant from the backpack fluid tank to the spray gun via a diaphragm pump. The disinfectant then sprays from the trigger sprayer nozzle onto a surface to be disinfected.
The ruling explains that 
the Electrostatic Backpack Sprayer, consists of at least two different articles that are classifiable in different headings and consists of articles put up together to carry out a specific activity (i.e., spraying disinfectant). The articles are put up in a manner suitable for sale directly to users without repacking, and thus is within the term “goods put up in sets for retail sale.” GRI 3(b) states in part that goods put up in sets for retail sale, which cannot be classified by reference to GRI 3(a), are to be classified as if they consisted of the component that gives them their essential character. CBP concluded that the Electrostatic Backpack Sprayers’ essential character is imparted by the trigger-activated spray gun.
CBP determined that the applicable subheading for the Electrostatic Backpack Sprayer is 8424.20.9000, HTSUS, which provides for “Mechanical appliances (whether or not hand operated) for projecting, dispersing or spraying liquids or powders; fire extinguishers, whether or not charged; spray guns and similar; steam or sand blasting machines and similar jet projecting machines; parts thereof: Spray guns and similar appliances: Other.” The rate of duty will be free.
Pursuant to U.S. Note 20 to Subchapter III, Chapter 99, HTSUS, products of China classified under subheading 8424.20.9000, HTSUS, unless specifically excluded, are subject to an additional 25 percent ad valorem rate of duty. At the time of importation, 9903.88.03, in addition to subheading 8424.20.9000, HTSUS, must be reported.