The 504HD’s patented Bridging Technology allows for a wider top plate and longer sliding plate that add stability and balance to a set of state-of-the-art professional features. A newly designed counterbalance system includes four presets–from 0 to 16.5 lbs–enabling proper balance for camera loads up to 19.8 lbs, while 3/8″ threads in the top plate allow attachment of monitors, arms, and other accessories directly to the head.