Humm Dinger Vibrating Cockring - Glow in The Dark You will be able to see this in the dark! Glow in the dark with this super stretch one size fits all vibrating textured cockring and clitoral stimulator. The vibrating bullet has an easy on-off rotating dial with battery included. The powerful vibrating action is for his and her pleasure for at least 20 minutes of continuous action. This Night Rider is meant to please.