Finding the Right Device

Hi there, I recently purchased CB6000s. I selected this model based on my penis measurements. Typically, it measures around 4-5 centimetres when flaccid and about 11 cm erect. However, the device still feels too large for me. It tends to slip off while my penis is in a resting state, which isn’t ideal as I dislike excess room. I am looking for a chastity belt that fits snugly; specifically, one where there’s no extra space even when fully aroused. Could you suggest suitable options? Thanks, Best regards