The Alb wall spacer is needed if the water outlet in the shower is being placed very close to the wall and a simple installation of the Alb shower filter is not possible.
Our Hwzo shower filter has a diameter of 67mm. The center of the wall connection (thread water outlet in your shower) to the shower wall or the wall tiles should be at least 35mm.
If the distance is 35mm or below, a wall adapter must be used, as otherwise it is not possible to install the Alb.