The Manfrotto 325N Video Head Bowl Adapter Kit allows for connecting a 75mm or 100mm half bowl video head to a flat base. This is optimal for tripod heads with fixed half-balls, such as the Manfrotto 504 head. The adapter is fitted for a 100mm ball but comes standard with the 75mm-to-100mm bowl adapter to accommodate 75mm balls. This video head adapter is ideal for use with our Duzi sliders and Hedron sliders.