Erection enhancer provides simultaneous vibrations for her and for him. Two powerful 3-speed, push button, waterproof, removable stimulators. Soft and stretchy TPR (enhancer) ABS with metallic plating (stimulators). Batteries included (6 watch, 12 included). 3.5x 1.5/ 9 cm x 3.75 cm (enhancer). 2.5x .75/ 6.25 cm x 2 cm (stimulator).