Because of problems with the intervertebral disc have been looking for an increase for my Treckingrad of BULLS - and found. The device comes complete with new screw and fits perfectly. The optics I find ok. The sitting posture is better to classes. As a new bike. As already described: Only tighten the new, center screw, then the remaining screws. That nothing wobbles. The quality is right - the price also. From me there is a perfect score.