Diameter increases by 15 mm within 12 seconds (max.) when inflated, from about 4-4,5 cm to 5,5-6 cmAdjust the diameter individually by stopping the button at the desired size. To release the air and reset the diameter, simply double-click the buttonCurved drop-like shaped shaft with total length of 17,5-19 cmLooped handle for easy usageOne powerful motor with 12 vibration programs/