(Baseball Kingdom Original) Soft Tennis Ball Practice Balls 12 Balls Same Quality as a Practice Ball from famous brands. After passing the same rigorous inspection as famous brands, the original baseball Kingdom soft tennis ball practice ball is born.High quality soft tennis ball with less rotationUse as a practice ball that is a step above the Wakarei product. [Precautions for Use] "Soft Tennis Baseball Kingdom Original Practice Ball" is sent to customers with reduced air pressure to prevent rubber deterioration etc.Please be sure to inflate the product before use. [Product Description] Valve system for safe and secure air adjustment.The soft tennis ball has a thin skin of the ball itself will not keep the air constant for a long time.Make sure to check and adjust the air pressure before playing.Always use a valve pump when adjusting air pressure.If you apply a commercially available silicone oil to the pump needle, it will be easier to enter the hole and make it easier to inflate. ■How to adjust the air : Insert the needle vertically at the center of the valve to the base.Push down the pump hole with your thumb, repeatedly release the pump to adjust the air pressure.Remove the needle slowly and vertically. Material: Rubber. *Soft tennis ball.Do not use for anything other than the intended purpose.