John Lewis office chair (Upminster RM14)

Grey office chair from John Leiwis (RPR £175 at the time). Has an issue with piston and changes height randomly and inconsistently. Seems fine with a lighter weight person :). Other than that It is in impeccable condition no stains or marks at all and I am sorry that it'snot working as well as it used to. Pet free smoke free house, and one of the most comfortable chairs we've had, but unfortunately I can't replace the piston, so posting here in case someone could make use of it, before it goes to the council collection.