That is right 8 levels of powerful stimulation delivered by the Double Action Arousers! The silver bullets 2 have an exquisitely textured, soft, supple, removable Thermoplastic Rubber TPR purple sleeves. The easy touch control pads with LED displays have a contoured case for ergonomic versatility. Vibrator uses 4 AA size batteries, not included. The power behind the Double Action Arousers is indescribable, it will take your breath away! Twice!