The clamping bore of GN 273.4 sensor holders is mechanically machined and designed for construction tubes GN 990 or DIN 2391, DIN 2395 and DIN 2462 respectively. The standard version of the clamping screws are socket cap screws with hexagonal socket DIN 912. It can be replaced by a clamping kit GN 911 (article code see table of dimensions). The aluminium design guarantees a highly safe and secure clamping action and safe positioning.