The EC3 blends elegance with function, featuring it's double needle stitching that provides strength and durability with a dynamic ergonomic back suspension system that's integrated into the molded back. The EC Collection's 3 Series is available in executive high back and mid back management / conference models. Standard features: / Synchro-tilt mechanism includes multi position tilt lock with slow release, pneumatic height adjustment and side tension control. / High density, high resiliency, molded seat and back foam for comfort and durability. / A full back, dynamic, self-adjusting spring support system, embedded into the molded foam back. / Fixed height, polished aluminum arms with polyurethane arm pads. / Waterfall seat design to reduce muscle fatigue. / Built in headrest support. / 5 Prong polished aluminum base. / 3" Dual wheel carpet casters.