These are tongue and groove fence boards and can be used any way other tongue and groove boards can.
channels on the posts are 3/4" and the boards are 5/8"
No it only comes in 71" sections.
Yes it does.
this board is approximately 5 inches tall and is tongue and groove.
Samples are available, please call 800-955-2879 and ask for samples to be sent.
The length is 5.91' and is mentioned in several places including the description of the board. 0.41' H x 5.91' W.