Maximum of 18 stonesThese posture chairs have high back height and are overall operator chairs and office chairs. Some items have inflatable lumbar support to maximise the support given to the lower back while others have a kidney shape back for back support too. Some chairs come with arms and others without, however they are a sort of variation of similar-looking chairs differing in their features - in addition, if you suffer from back problems and want to try something different, we have a kneeling office chair worth checking. Maximum of 23 stonesThese chairs are sturdy and durable, suitable for twenty-four hour use without sacrificing comfort as these posture chairs have mechanisms which allow great adjustability and customisation, such as the seat height and adjustable arms. Ideal for call centres and control rooms, the price range of these heavy duty chairs goes from £100 up to £500.Maximum of 28 stonesThese heavy duty chairs are what we have best in sturdiness and strength, chairs perfect for call centres and control rooms too or any other busy environment which requires twenty-four hours of use. All chairs have high back height (65cm) and allow height adjustment of seat and arms - what's more we have items made of fabric or leather as well as items available in black or blue.