Tennis balls fall into two groups. Pressurised balls are what you play matches with, livelier off the racket, but the internal pressure escapes within weeks of opening the tin whether you use them or not. Pressureless balls take their bounce from the rubber itself, so they last far longer and are the sensible choice for practice baskets, ball machines and coaching. Buying for children, the stage matters: red and orange balls are slower and lower bouncing, so a rally is actually possible. Babolat, Wilson, HEAD, Dunlop and Tecnifibre are all stocked. See also
tennis rackets and
tennis bags.