The Doc Johnson Classic Butt Plug is the original and the best!
These butt plugs are made from soft non-toxic rubber and available in three different sizes, and in two different colours.
Fantastic value!
4.5" x 1" (small)- 5.5" x 1.5" (medium)- 6" x 2.25" (large) - 110mm x 25mm (small)-140mm x 40mm (medium)-150mm x 60mm (large) - None Required