Some jib arm makers advertiser the "reach" of their jib arm from the pivot point of the tripod to the head. This is useful in calculating how far the camera can travel in an arc.

Other jib makers measure the total length of the arm, from the counterweights to the head, which makes calculating the arc a little harder because I don't know where the pivot point is.

I see Kessler 12 and 18. Is that the total length of the arm, or is it the reach?

It is the total length of arm and not reach.

Thanks Chris!