The BH-55 Ball Head with Full Size Screw-Knob Clamp from Really Right Stuff is a 1.9 lb ball head that will support large camera/long lens combinations weighing up to 50 lb. Crafted from aluminum and stainless steel, the BH-55 has all of the features you'd expect from a professional-level head. An over-sized, ergonomic locking knob allows 45-degree tilting in all directions and dual 90-degree drop-notches facilitate quick and accurate switching from the horizontal landscape position to vertical portrait orientation. A separate tension knob is provided to apply the appropriate pressure that safely corresponds to the weight of your camera. A third knob loosens and locks the panning base which is laser-engraved with markers every 2.5 degrees from 0 to 360 degrees.