Identify Pre-Engineered Paver Notches

What happens here

For certain paver types, specifically mentioned as 'Unilock Lineo', the gaps are pre-engineered into the pavers themselves. The speaker demonstrates these built-in notches on the sides of the pavers. These notches prevent the pavers from sitting flush against each other, automatically creating the desired uniform gap when they are laid side-by-side. This design simplifies the installation process by eliminating the need for external spacers for this specific paver type.

Goal: Understand how some pavers are designed with built-in gap-creating features.