Primo is made of environment friendly silicone, it past all the strict tests and reached high standard before going to the market. Primo has 5 different modes, and 5 intensities in every mode, so you have 5 x 5 = 25 selections. More ways for you to explore. Despite of Primo's small size, the motor inside of his silicone body still lives up to your strongest desires. Primo is designed with pinhole charging port, and it's completely waterproof. Do it in the shower, in the bathtub, in your swimming pool, wherever you pleased. Primo is equipped with a heating core which can heat the vibrator up to about 38℃/100.4℉ to provide a better satisfaction, especially during winter.