Description
The Seco Swiss Style 62 mm Nodal Point Prism Assembly (GPH1-style) is a survey prism made by Seco (part number 6406-00).
Its absolute prism constant is -34.0 mm, which is +0.4 mm on the Leica scale.
Specifications
| Model: | 6406-00 |
| Manufacturer: | Seco |
| MPN: | 6406-00 |
| Status: | Current |
| Height Offset: | 86.0 mm |
| Absolute constant: | -34.00 mm |
| Leica constant: | +0.40 mm |
| Constant source: | Manufacturer documentation |
| Prism diameter: | 62 mm |
| Weight: | 420 g |
| Mount: | Swiss-style quick release |
| Coating: | copper |
| Equivalents: | Leica GPH1/GPR1-style (Swiss) holder; -34 absolute is close to Leica 0 (Leica standard prism = -34.4 absolute) |
| Last verified: | 21/10/2026 |
Sources
Seco Swiss Style 62 mm Nodal Point Prism Assembly (GPH1-style) FAQ
Below is a list of frequently asked questions about Seco Swiss Style 62 mm Nodal Point Prism Assembly (GPH1-style).
What is the prism constant for the Seco Swiss Style 62 mm Nodal Point Prism Assembly (GPH1-style)?
The absolute prism constant for the Seco Swiss Style 62 mm Nodal Point Prism Assembly (GPH1-style) is -34.0mm. The Leica constant is 0.4mm.
Can I use the Seco Swiss Style 62 mm Nodal Point Prism Assembly (GPH1-style) with a Leica instrument?
Yes, just set the prism constant to 0.4mm.
What is the height offset of the Seco Swiss Style 62 mm Nodal Point Prism Assembly (GPH1-style)?
The height offset is 86.0mm.
