These are one of my favorite pellet treat balls. This rubber ball is absolutely perfect for dropping pellets out as well as for teething. Pigs will get 3 sets of teeth so they are always teething. I find this rubber ball to be very well made and seems to be indestructible. Circumference is 16", 11", & 9". 

Rubber Treat Teething Ball Combo Pack - 16", 11", 9" Circumference