rh logic 400 with headrest The balanced rocking movement has three main benefits: Continuous support of the seat and back whether leaning back whilst relaxing or sitting forward to address the keyboard, increased blood circulation to the lower limbs to reduce fatigue caused by static posture and an adjustable lumbar pump. Note : Product comes with headrest as shown The tilt mechanism is infinitely adjustable, with a smooth action that can be locked in any chosen position. Dynamic seating means the chair follows your every movement regardless of working position providing complete support, enabling you to always sit correctly and breathe properly.