Probably the simplest and most robust ball on the market, there is just one hole which capably handles easy filling and slow discharge. There are no plugs, stoppers or other removable parts to lose or break. The brilliant lumpy styled ball seems to have a mind all of its own and dos not go in a straight line. Moulded from ultra tough stubbythene (which is tested for impact, strength at icy temperatures) this is a tough horse toy is supremely durable. And dogs love them too.