Zolo Back Door Cup Blue. The Zolo range gives a fresh and funky look to one of the oldest activities known to man! There are seven Zolo Cups, each with a shaped, nodule inner chamber for the most intense stimulation: Design Features: Zolo Cups feature an ergonomically designed outer case that contours to the hand for a better controlled grip. Zolo Cups’ proprietary, real-feel material is soft and warms to the touch for unique sensations that are even better than the real thing. Some like it tight, others like it loose. Whatever suction you want, Zolo’s air control feature adjusts for your desired tightness.