I purchased a pair of these to allow me to install a grid of Unistrut type metal channels on the roof of my workshop by myself.  Turns out I only needed but one for that task.  I would lean the 3rd Hand against a ladder and then climb the ladder with the strut in one hand.  I would place the center of the strut where it needed to be and hold it in place with one hand and then grab the 3rd Hand with the other and place it under the strut and then squeeze the lever to clamp it against the strut to hold it in place against the ceiling.  I could then start installing fasteners to attach the strut to the ceiling.  I also purchased the 3rd Hand laser attachment clamp and have projects where that combination will also come in very handy.  The supports were easy to adjust and operate and were sufficiently sturdy to apply sufficient clamping force to hold steel struts in place against a ceiling. I never felt my head bone was in jeopardy as I proceeded with work on the ten foot long steel channels clamped against the ceiling.