The pistol uses dehumidified compressed air as propellant for the diabolo air gun pellets. The rifle uses dehumidified compressed air as propellant for the diabolo air gun pellets. Holes and metal strips alter the sound of the spinning diabolo, but create friction. Another advanced diabolo style is "vertax" (vertical axis; also known as "Excalibur"). Skilled users can perform multiple tricks while maintaining the spin speed of the diabolo. Five people visit a fairground sideshow run by showman Dr. Diabolo (Burgess Meredith). In 1977, his soundtrack to Diane Kurys's film "Diabolo Menthe" was well received. For the 10 meter air rifle and air pistol disciplines, match diabolo pellets are used. The most basic act of diabolo manipulation is to spin it on the string. Examples include catching the diabolo between one's arm and the stick before throwing it back. It utilizes the diabolo so that it has little or no spin at all. In his magazines he promoted toys such as the diabolo. Phillipart claimed "Diabolo" to be his invention. This is a relatively recent style of diabolo that is gaining popularity. The Diabolo project is a public-private partnership.