Premier Youth Tennis: Since its inception in 1990. Insum Premier Youth Tennis is proud to introduce new players to the sport through innovative introductiory and recreational programming and equipment options that make it easier to learn,play and enjoy tennisHow to choose a correct size racket for your kids: There are two vital factors of choosing proper tennis rackets, one isthe length of the racquet and the corresponding age, you can compare below table for details.The other is the distance from Wrist to Ankle should match the racket length.We Recommend: Insum 17 Inch: Ages 2-4 Years/ Tall 30-34? Insum 19 Inch:Ages Up to 4 Years/Tall 35-39? Insum 21 Inch:Ages 5-6 Years/Tall 40-44? Insum 23 Inch:Ages 7-8 Years/Tall 45-49? Insum 25 Inch:Ages 9-10 Years/Tall 50-55?Quality Insum introduces a quality racket line specifically designed with a youthful & fun focus. This unique racket range consists of: 17?,19?,21?,23?,25?. Each of these unique rackets have been specifically designed. To complete the ease of play, Insum is helping kids to really enjoy tennis with special (ITF approved) tennis balls, each being color-coded to the differing stage model?s ball compression! All Insum junior and youth racket lines are designed with Fischer Racket Technology, delivering the performance characteristics and proven learning concepts as designed under the: ITF ?PLAY + STAY? Tennis Teaching Philosophy.Each purchasing come with guidence brochure to know the commission of each stage.Racquet Info: Grip 0000:Ideal Grip size for 2-4 years specially. 5.0-5.30oz Light Weight. Powerful String Tension:35-40LBS,string pattern:14*16 Head size of 75sq.inPacking: 1x tennis racket,1x racket head cover,1x Racket/Ball/Court Guidence Brochure