This high end animation has to be seen to believe! Constructed out of a soft and stretchy silicone, the spider egg sac pulsates in a random and organic motion, imitating a spider getting ready to hatch from within. Definitely a very unsettling set of movements that will creep out your guests and prepare them for whats about to come. Buy several animated and several static sacs to make an unforgettable entrance to your spider lair. runs on 50 psi and 110vac. controller and trigger included.