For external application to the udder only after milking, as an essential component of udder management. Plastic backpack sprayer comes with18V lithium-ion battery and charger. For use with Udder Comfort Backpack Sprayer Mix or Udder Comfort Yellow Spray (sold separately). Features adjustable straps and a 28"L wand. Battery lasts approximately 4 hours; takes 3.5 hours to fully charge. To clean spray nozzle, flush with water.