Amazon has the 4-Pack Outward Hound Squeaker Ballz Tennis Ball Dog Toy (Medium) for $4.07 - $1.22 off coupon (check "Save an extra" box, eligible on first S&S order for this product) = $2.85 with free shipping on $25+ or with Prime (extra 5% off with 5+ items S&S order). Squeaker Ballz are only intended for dogs under 25 lbs.