This series has 12 models, including 10 regular models, 1 surprise model, and 1 hidden model. The probability of getting a regular model is about 9.31%, the probability of getting a surprise model is about 5.56%, and the probability of getting a hidden model is about 1.38%. That is, for every 72 models, 4 surprise models will randomly replace 4 regular models. That is, for every 72 models, 1 hidden model will randomly replace 1 regular model.
