My set has been in a rental property I own for the last two years and I haven't had access to the unit till now. The chair legs have rust at the bottom and have left many rust marks on my travertine floor, and as I turned one of the chairs upside down to check what was under the legs, a black liquid leaked out. The set is in a covered balcony. 
Aluminum doesn't rust, therefore there is some other metal in these chairs that was not described. Very disappointed, and do not recommend. You get what you pay for.