Firefly Prince Medium Purple Butt Plug with ring end from NS Novelties. The Firefly Prince Glow in the Dark silicone plug is designed with your pleasure in mind. Firm, supple and suitable for all lubricants. Available in assorted colors and sizes. When the sun does not shine, you make your own glow. Product dimensions 5 inches by 2.3 inches by 1 inch. Product material Silicone.