This is a pressurized storage case for tennis balls, an alternative to commercially available Ball Rescues and Ball Savers. (Pressure retainer) 【Important Notes】 ※ Please understand that this product will be shipped in simple packaging using bubble wrap. ※ This product is actually pressurized with balls before shipping. We have confirmed that there are no problems with use before shipping, but there have been claims of cracks. Please contact the administration for any damage during transportation. (There appears to be something like a crack in the last photo, but this occurs during the manufacturing process of Sekisui Chemical, the manufacturer of this product, and does not affect the use of this product.) ※ Only the storage case is for sale. An air pump, tightening rod, balls, etc. are not included. Other tools are also not included. ※ Before inflating, make sure that there is no sand or felt on the screw part of the lid and the O-ring. This can cause air leaks. ※ Never pressurize above 1.5 atmospheres. There is a risk of the case bursting or the lid flying off and causing injury. We recommend using around 1.0 atmosphere as the balls will become too hard. ※ Balls with felt that tends to expand (such as Dunlop Fort) may be difficult to remove. In that case, shake this product up and down to remove them. ※ This is a handmade product, so please understand that there may be clouding of the adhesive, polishing marks, scratches, dirt, and adhesive application for sealing purposes that occurred during manufacturing. ※ We cannot guarantee any damages caused by the use of this product, so please purchase with your understanding. 【Request】 We have received complaints from customers who purchased the product without understanding the contents listed in the product description. Please be sure to check the important notes before purchasing, and if you have any questions, please inquire in advance. We will provide careful support regarding how to use the product, but we cannot respond to requests for replacement products if you unilaterally claim a defect. Thank you for your understanding.