I was called to a customer's home to change a filter and check the charge and operation of their cooling system. Upon arrival, I found that the customer had recently purchased a new filter and wanted me to check the charge and operation of the system. I performed a thorough inspection of the system, including checking the refrigerant levels, inspecting the condenser coils, and cleaning the drains. After completing the inspection, I found that the system was cooling properly and the charge was within the manufacturer's specifications. The customer was pleased with the service and thanked me for my help.