Instead of just plugging someon's butt, you can open it and use the tunnel hole that goes all the way through the plug. Besides the unbelievable sensation, you are actually able to see right into it. Use your imagination and go wild, or easily insert fingers or lube right through the plug. It is made of special blend of silicone and TPR called PF Blend. It is available in clear, black, or red. It is safe with water based lubes. Wash thoroughly with mild soap and water. This product is not compatible with latex. The extra large has an insertable length of 4 inches, with a circumference of 9 inches.