The ThunderX3 Flex Pro is a premium mesh ergonomic chair offering nineteen dimensions of adjustment, built around a SYNC6 multi-functional synchronous-tilt mechanism and a Class-4, BIFMA-tested gas lift for a higher 150kg rated user weight than ThunderX3's standard range. It has fully 6-directional (6D) armrests, a 2D adjustable headrest, and a self-adjusting backrest with spinal-fit technology that flexes to the user's shape rather than a single fixed curve. The base spans 350mm with 75mm casters designed for quiet rolling on hard floors. Overall footprint is roughly 70cm x 70cm with a total height of 129-137cm, seat sized at 54cm W x 53cm D with height adjustable from 47-55cm. Aimed at users who want the most adjustable option in ThunderX3's ergonomic mesh line -- long gaming or work sessions, larger users up to 150kg, or anyone who wants fine-grained control over every part of the chair. Ships flat-packed with the seat, backrest, base, gas lift, casters and armrests separate, plus hardware and instructions for home assembly.