The swing mechanism enables the seat to be tilted into every direction without a separate adjustment lever. This enables the user to exercise while sitting, which adds to the mobility and metabolism of the lower back and activates the whole body. Recommended to all with low back pains or desire to have the healthiest possible seat for their lower back metabolism. Hand controlled height adjustment with gas spring Weight of the chair 11.5 kg Upholstery black leather or artificial leather, see colour chart Warranty 5 years for chair upholstery and frame, including the seat, castors, mechanism, gas spring, and base