Guys, get loud about men's health awareness! Make some noise and bring attention to an important cause. Keep healthy, and encourage others to do the same with the help of these mylar boom sticks. They're great for rallies, fundraisers, benefit walks and anywhere else you want to make a statement about your engine. After you inflate, seal the self-adhesive tab to keep the boom sticks from deflating. To achieve loudest noise, keep the boom sticks vertical when hitting them together. Mylar. (2 dozen per unit) Inflated, 23" x 4"; includes 4" blow stick.