It comes with an influence twine, or you can use it with D batteries. You can also modify the angle of the direction that the ball is thrown. A variety of the ball launchers above are the sort to work even with lots of slobber and dust https://smartdogstuff.com/dog-ball-launchers/ifetch-ball-launcher/ within the mechanism, however a bit of cleaning goes a long way. Making sure your dog’s ball launcher...