Details about the Libre seat
The seat consists of a hot-dip galvanized, polyester powder coated steel structure consisting of three thick sheet steel supports connected by a strong horizontal steel tube rod, which also connects to a seat formed from drawn steel tube sections. The polyester powder coated cast aluminum poles, which can be supplied with a variety of positioning and ground mounting kits, are secured to the boom using custom coated cast aluminum clamps. As an alternative, hot-dip galvanized and polyester powder coated tubular steel supports are available for in-ground concreting.

https://www.artformurban.co.uk/metalco-libre-seat.html