Comes in two sizes :Model A Smaller or Model B Larger. Model A: Is a great compact size, with all the features of the larger model B. Model B: After your cock is to large for model A, you will step up to the EXTRA power and volume of model B. Both model A and B have powerful rubber hand-pump. Push button pressure release. Pressure power booster dome. High-quality plastic housing. Soft rubber cockring.