The 4 levels of EHS, or the Erection Hardness Score
Grade 4 or “Optimum” erection is the highest level which can be likened to the hardness of a cucumber. It not only helps achieve sexual satisfaction but also indicates a generally healthy condition among men.
Grade 3 or “Suboptimum” erection, which is hard enough for penetration but not as hard as Grade 4. It can be compared to an unripe banana.
Grade 2 is not hard enough, like a peeled banana.
Grade 1 is likened to a serving of tofu.