Magnetic Rail Versine Measuring Kits is also called string box for railway curve measurement. It is a necessary tool for railway works construction. Curve positive vector measuring box is a regular work in rail line maintenance. In order to facilitate the work of the worker to complete this job, a new line curve positive vector measuring box has been development. Feature Curve versine measuring box is a fine production, it is portable, pocket, and good looking. The box body resistant ABS material for yellow, and easy to operate.