What is the diameter of the seat post on Citizen folding bikes? I have searched and cannot find the diameter of the seat post.

I would like to get their Miami or Gotham model, but I know I'll need a seat extension as a 6'2" rider.

Dahon and others make longer seat posts, but I need to know the diameter in order to ensure a fit.

Anyone know the Citizen seat post diameter? Is it 33.9 like the Dahons?
The seat post dimension for Citizen bikes, according to customer support, is 31.8mm.