i have purchased 3 of your zisc disc's and have been very happy with them. i watch my daughters dog alot and she loves playing catch. the first zisc is about 4 months old and she has finally got some splits in center which she now tries to enlarge. i believe if you could reinforce the center with say a fiberglas mat inside it would stop bite holes from propagating into splits , also i would taper rim edge between center and top flange to make it harder for dog to get purchase when trying to remove from mouth. again it is a good product made in america (i always look)and will continue to buy. a good tip for not having to pull toy from dog as that is where most of the bite holes come from is to use two zisc discs. lulu drops one as soon as i start to throw second one.