Humm Dinger Cock Ring Clitoral Stimulator Purple. The Humm Dinger is a portable vibrating cock ring that can fit any size penis because of its super-stretch material. It offers 20 minutes of continuous vibration and an easy on/off switch. Batteries are included for immediate use. Cock rings when worn around the base of the penis and testicles, many users find that cock rings increase sexual pleasure. Prolong rings, erection enhancement, climax control rings, cock rings. Phthalate free, non-toxic materials: Thermoplastic Rubber TPR. Shown in pink, ships in purple. Hott Products Unlimited.