2 ½ height Adjustable Chrome gas cylinder.
4 leg base polished metal 28" diameter.
Casters upgraded to bright metal, full hood, double wheel for all types of flooring.
Swivel and rocker height adjustable seat mechanism SKU 3318G--6" X 10" hole slots on centers.
Rock and Swivel 3318G: Floor to top of mechanism with casters, base, gas cylinder, and swivel tilter mechanism-Low is 15 1/2", high is 18".
Simply insert without tools the gas cylinder into the center hole of the 4 leg chair base. Just sitting in the chair several times will make extremely tight and require tools to remove.
A mounting board may be necessary to install SKU 3318 or any other size mechanism.