Choosing roller shutters is to choose security and energy efficiency. With the new aluminium slat, the ALU42, Harol is taking another step to meet these needs, without losing sight of design or comfort. Its new foam core, which is 20% more rigid than a standard foam core, makes the ALU42 even more resistant to wind and rain. The aluminium slat has 15% higher torsional resistance and an 11% lower risk of damage from hail when compared with slats with a standard foam core. Moreover the ALU42 has improved thermal insulating properties with a delta R-value of 0.16 m²K/W, as well as better noise insulation. The new slat shape attenuates noise from outside better and the roller shutters can be rolled up into a more compact space. ALU42 is available in no fewer than 28 colours, making it the most colourful aluminium slat on the market. This broad palette allows the slat colour to be perfectly matched to the box, the home and the joinery. The result is a roller shutter that fits in seamlessly to your home.