Renya, thanks to the mechanisms used, allows 100% back support. Research at MDD has revealed that traditional chair models do not support the lumbar spine in an inclined position. In order to counteract this phenomenon, we have developed a backrest with an adjustable tilt point within the range of 8 cm, with an additional range of movement of +/- 30 degrees. This effect is provided by one setting, which is an advantage of the chair over traditional solutions that require multiple adjustments. -Renya, thanks to the mechanisms used, allows 100% back support. Research at MDD has revealed that traditional chair models do not support the lumbar spine in an inclined position. In order to counteract this phenomenon, we have developed a backrest with an adjustable tilt point within the range of 8 cm, with an additional range of movement of +/- 30 degrees. This effect is provided by one setting, which is an advantage of the chair over traditional solutions that require multiple adjustments.