Tether Tools Rock Solid 2-Head Tripod Cross BarRock Solid 2 Head Tripod Cross Bar Combine the Rock Solid 2 Head Cross Bar Side Arm with the Rock Solid 4 Head Tripod Cross Bar to create the Tether "T" setup enabling easy adjustments to the cameras height. The Tether "T" design allows the computer to remain at a constant height, secured on the Rock Solid Tripod Cross Bar, while the Rock Solid Cross Bar Side Arm provides a height variable solution that is perfect for step and repeat photographers.