Yinhe table tennis umpire standard net measurer ruler for professional table tennis games ping pong and a measurer for rubber thickness.
The law of high net post by ITTF
The net shall be suspended by a cord attached at each end to an upright post 15.25cm high, the outside limits of the position being 15.25cm outside the side line.
The law of thickness rubber by ITTF
A side of the blade used for striking the ball shall be covered with either ordinary pimpled rubber, with pimples outwards having a total thickness including adhesive of not more than 2.0mm, or sandwich rubber, with pimples inwards or outwards, having a total thickness including glue of not more than 4.0mm.