In very good vintage condition with minor wear/discoloration to fabric, and normal wear to the metal base and top. All inner mechanisms to adjust are in working order. I do not know the size of this a, b etc.
But it's approximate measurements as is are as follows. Height at lowest (from base to top of the knob): 38.Over 6 feet tall when fully extended (from base to top of the knob). Please look at all photos carefully for condition.