The Jobu Design BWG-J2 Black Widow Jr. 2 Gimbal Tripod Head is a gimbal-type tripod head that allows the entire weight of the camera and lens combination to be hung rather than balanced.
This Gimbal design allows the camera to be sidemounted rather than to be placed on top of a ball head. This is especially useful for larger telephoto lenses or spotting scopes. This way the lens can rotate around its center of gravity, dramatically improving handling and vibration dampening.
The Jr. 2 is useful for small-to-medium
telephoto zoom lenses with a rotating tripod collar, such as: 100-400mm f/4 lens, 70-200mm f/2.8, 50-500mm, etc.