The Nerf Dog LED TPR Balls have been designed to keep your pet entertained for hours on end. Made of tough thermoplastic rubber, this toy will stand up to extensive chew sessions. Ideal for toss and fetch or solo play sessions. And, it floats. These balls is suitable to go in the Nerf Dog Tennis Ball Blaster, watch them light up and they blast down the barrel. Compatible with the Nerf Dog Tennis Ball Blaster and Translucent Blaster Made from TPR LED lights inside the balls Approx size 2.5" diameter