Chair is excellent. Very comfortable with good support. But footrest needs extra work. The locking nut fixing the footrest in position cannot be tightened enough to stop the footrest from slipping down each time I mount the chair.(The footrest must carry the whole body weight each time the chair is mounted.) I have fixed this problem as follows: Take a scrap length of standard plastic plumbing pipe measuring 50 mm internal diameter. Cut off a piece (nicely square) approx. 70mm long. Next, use your hacksaw to slice this piece lengthwise down the middle, creating two identical semi-circular shells. Finally, clamp these shells around the column of the chair using an adjustable hose clamp (of the type used for automotive radiator hoses). The footrest will now be unable to slide down the column. ( I spray-painted the additional parts black to preserve the nice appearance of the chair.)