Master Series Invasion Hollow Silicone Anal Plug Small Black. This darkly sexy anal plug has a thrilling feature that allows unrestricted access to their innermost areas! The hollow plug is made of a semi-rigid, premium silicone material that is soft enough to enjoy while staying strong enough to keep them spread open and ready. The flared base and tapered tip keeps it in place, even during vigorous use. Measurements: 3.75 inches in total length, 3 inches insertable, 1.5 inches in diameter at widest point. Material Silicone. Color Black.