The present paper suggests a simple model to predict the mass flow rate and the slip velocity ratio of a choked two-phase flow, at a wide range of void fractions and upstream pressures. It is postulated that since the critical pressure ratio of two-phase flow resembles the critical ratio of vapor (gas phase) flow, the vapor phase controls the pressure profile of the mixture. The model assumes frozen flow. Although the classical homogeneous model is suitable to predict the mass flow rate and the slip velocity model is suitable to predict the slip velocity ratio, the present model predicts both the mass flow rate and the slip ratio between the gas and the liquid phases. A brief comparison between published experimental results, these two classical models, and the present model supports our basic postulations. The present work thus proposes a grounded, simple-to-use and practical model.