In the course of the energy transition novel solutions are needed to solve challenges that arise. Many customer owned energy resources become connected and shall contribute to the demand-supply balancing process, eventually. Small size suggest to solve related volatility issues also locally. Flexibilities of customer appliances provide the means to mitigate/manage the impact of volatile energy production close to the source. This paper presents an approach to rate appliance specific flexibility offers. Provider and user needs are addressed independently via the metrics benefit and quality. Introducing the problem and the proposed 2D-rating, we sketch exemplarily how PV and electric room heating flexibility can be predicted, offered, and used.