Mini Tennis Mini Tennis Red (8U) Foam or felt ball used which is 75% slower than a standard yellow ballNet height (at centre) of 80 cmRacket sizes between 43 cm – 58 cm (17″ – 23″) recommended depending on size and strength of player Mini Tennis Orange (9U) Orange felt balls are used which are 50% slower than a standard yellow ballNet height (at centre) of 80 cmRacket sizes between 58 cm – 63 cm (23″ – 25″) recommended depending on size and strength of player Mini Tennis Green (10U) Green felt balls are used which are 25% slower than a standard yellow ballNet set to full heightRacket sizes between 63 cm – 66 cm (25″ – 26″) recommended but not compulsory Not sure what age group your child falls in for this season? Check what age group your child falls in for this season LTA Age Group Calculator