Product name: 

FORCED CENTERED BENCHMARK SUPPORT. Survey control point solution for millimetre-level alignment between the support and a GNSS antenna or total station.

Description: 

Forced Centering Benchmark Support (HCF in Spanish) for railway tracks. HM-20 concrete base measuring 100mm x 100mm x 60mm; PVC pipe with a diameter of 200mm Ø and 1.20m in height, fitted with an upper centering piece, a W5/8 screw and four positioning anchor points.

Web: 

https://www.grupoapellaniz.com/producto/hito-de-centrado-forzoso/