The article introduces a new model for interest rate markets that captures the different slopes of volatility smiles in European swaptions. By extending an existing model, the researchers create a framework that can be calibrated to market data and accurately represent volatility skew information. They develop formulas that simplify the calibration process and provide a new way to understand and apply volatility in stochastic models. This model has the potential to change how volatility calibration is approached in interest rate modeling.