Ball Stretching KitPleasurable ball stretching! The 3 piece ball ring set, Ball Stretching Kit from You2Toys, is perfect as a training kit for stretching the balls. The 1 cm ring should be used first for the stretching. Then the 2 cm ring can be used when the balls have been trained a bit. The widest ring (3 cm) should be used last this ring will stretch the balls the most. The rings can also be used together or separately. All the rings have an inner of 2. 5 cm. The