Provide a summary of the key characteristics of VELUX external roller shutters for roof windows, including their main advantages, available operation types (e.g., manual, electric, solar), and the material used for the slats.
Navigate to the VELUX website's external heat protection page for roof windows (https://www.velux.de/produkte/sonnenschutz-und-rolllaeden/hitzeschutz-aussen). Locate and navigate to the specific product page for 'Rollläden' (roller shutters). Identify and list the main advantages or benefits of the external roller shutters. Identify and list all available operation types (Bedienung) for these roller shutters. Identify the primary material used for the slats. Synthesize the gathered information into a concise summary.
State at least three key advantages of the external roller shutters (e.g., heat protection, darkening, insulation, noise reduction, security, privacy). List all available operation types: Solar, Elektrisch, and Manuell. State that the slats are made of robust aluminum. The summary is specific to external roller shutters for roof windows.