The Knapstein PIA-1 is a ceiling lamp with a square lamp shade. The light is diffused and evenly distributed downwards through matted glass. The lamp has a width and length of 18 cm each. The total height of the lamp is 5.2 cm. The ceiling housing is matt nickel-plated. Thanks to the magnetic holder, the lamp has a flat design and there are no visible screws in the ceiling housing. An LED with a colour temperature of 2,700 Kelvin extra warm white is integrated as the light source. The PIA-1 can be dimmed on site with a phase dimmer. The series also includes the larger square ceiling lamp PIA-4 as well as rectangular and round lamps.