In what scenarios are 12-inch traffic lights mainly used?

Choosing a 300mm signal for a specific installation

Start with the indication and the site

The 12-inch or 300mm label describes a nominal signal size. It does not establish the dimensions of the complete assembly or determine where the signal is approved for use. Identify the required colour and symbol arrangement, the intended viewing position and the applicable project specification before choosing a model.

A circular vehicle signal, a directional arrow, a pedestrian indication and a lane-control display perform different tasks. Select the required display for the application rather than treating every product with a 300mm designation as interchangeable. The installation designer should confirm placement and any visibility requirements.

Check mechanical and electrical fit

For a new installation, provide the proposed support or bracket arrangement and the space available for the full head. For a replacement, include measurements and photographs of the existing unit. Ask for the overall drawing, bracket spacing and service-clearance information for the proposed model.

Confirm the supply voltage, controller connection and any countdown or dimming function. State whether the order is for a complete assembly or individual modules. The quotation should identify included brackets, visors, cable fittings and other accessories so the installer can plan the remaining work.

Use the catalogue as a starting point

The catalogue can help compare section counts, symbols and housing arrangements. Request the relevant model data and project evidence before treating a listed configuration as the final selection. No single lens diameter guarantees a particular viewing distance or suitability for every road, warehouse or loading bay.

Send GAOQIAO the installation sketch, selected product reference, quantity and destination. Keep the approved drawing and configuration details with the order so that future spare-part enquiries refer to the actual assembly supplied.