This stainless steel hammerhead bolt M8x20mm + lock nut from Van der Valk with the Van der Valk product number 774221 was designed to screw the aluminum brackets (VDV-729520) to roof hooks and thus enable vertical mounting of the Side++ aluminum profiles to the roof ridge.

Stainless steel is a rust-free and weather-resistant metal.

Take a look at the installation videos for more information:

Click here to watch all the installation videos for a better understanding of the Van Der Valk installation systems and find the right system for your roof type.

You can also use the Van Der Valk planning tool to calculate your required components and you can view the installation instructions in the download section.

You can also consult our solar guide on common questions such as:

1. costs and income - Are solar installations in Switzerland worthwhile?

2. subsidies - Will my system be subsidized by the state?

3. steps to the solar system - Which individual points do I need to tick off?

And many more.