With the GloGerm Multi Kit you get four bottles of GloGerm Gel so you can train approximately 15-25 students per bottle, 60-100 students total. The Flash Light requires 3 AAA batteries not included. GloGerm products have been teaching proper hand washing and hygiene since 1968. Simply apply a generous amount about the size of a quarter to the hands making sure to get under nails and crevices. Shine the light to see the glowing simulated germs. Then have the student wash using their typical method. Most students are not very thorough at first and when the hands are inspected again it will show glowing material that was missed. Typically under the nails and in crevices around the knuckles and other areas. Then you can proceed to train using CDC and FDA recommended hand washing procedures. Makes a lasting impression on students, food safety handlers, medical professionals and others. Can also be used on surfaces to show areas missed. Start a hand washing training program today! Caution:Do not shine directly into eyes. Be sure batteries are installed properly