http://www.widersportsball.com/rubber-toys-ball/rubber-playground-ball/ Colorful rubber playground ball is composed of2 layers of foaming natural rubber + high content of butyl rubber. Colorful rubber playground ball The outer cover layer with a higher proportion of natural rubber provides a higher ball distance, and the nylon winding layer makes the ball a complete circle shape. And to keep constant, the butyl bladder is the basic function of maintaining the air pressure after inflation during the game. When we indoors we generally choose to play balls especiallybabies, when we use balls for a long time, the gas in the ball will slowly release, which will make the ball become insufficient air pressure. At this time, we need to give the ball, Increase the air pressure to make the ball more flexible.The balls with pebble surface are suitable for beach sand as a playyard. Indoors ball is a kind of r ball that can be inflated at any time. When the air pressure in the ball is insufficient, an inflator can be used to increase the air pressure to the ball.Rubber Playground Ball quotation website:http://www.widersportsball.com/rubber-toys-ball/rubber-playground-ball/