Close-up of the hydraulic boom control on a J.L. Fisher "Model 10" <a href="//commons.wikimedia.org/wiki/Camera_dolly" title="Camera dolly">camera dolly</a>. Off to the left you can also see the lever in the center of the steering column which sets the brakes.
<a href="//commons.wikimedia.org/wiki/User:Fadookie" title="User:Fadookie">Eliot Lash</a>
CC BY 2.5
<span class="int-own-work" lang="en">Own work</span>