The core activity of KLH AG encompasses three main areas: 1. **Energy Trading**: The sale of heating oil and fuels (gasoline, diesel) to private and business customers. 2. **Real Estate Management**: The management and rental of properties, including apartments, commercial spaces, and office buildings. 3. **Service Station Operation**: The operation of service stations at various locations, including the sales outlets in Oberentfelden and Staffelbach. These activities are the main sources of revenue for the company and form the core of its business operations.