Sintered hard metal quality grinder mechanism made in Denmark. Finished height of mill approximately 406mm (about 18 inch). Actual shaft length 403mm. Fits in 24mm diameter hole in barrel. Requires recess for 34mm diameter flange set 8mm deep in base. Brass knob has coloured dot for distinguishing between pepper and salt mills (black for pepper and white for salt).
Shaft is 4mm square section steel. Grinder is held in by steel strap in base (screws not supplied)
It is possible to shorten the shaft by cutting down the bottom end and swaging with a hammer to retain the inner grinder. This saves having to re-thread the top of the shaft.
The image is of the 4" grinder.
Matching 18 inch salt mill not available sorry.