A Rod Blank is simply the spine of the fishing rod with out any components installed on it such as guides, handle or reel seat installed.
A Rod Blank is NOT fishable in the form of a blank. Rather the blank is sold to a Custom Rod Builder who will in turn install your choice of guides, reel seat and grips to the length and postion that you desire. Some seasoned customers will build fishing rods themselves.
Many consider the highest level of the sport is when an angler builders reaches the skill level to custom build (wrap) his own rods and also build his or her own lures, jigs or poppers with this own two hands.