Hydration Bag 3L Backpack with Rain Cover

This is a brand new, unused item.
It is a product that costs around 5300 yen on Amazon.

[3L Hydration Pack for Hydration Anytime] Comes standard with a 3L large-capacity hydration pack made of food-grade material! The improved leak-proof design eliminates worries about water leakage. The high-flow bite valve tube allows for easy hydration while riding or hiking. An emergency whistle is also included to enhance safety during outdoor activities.
[Insulated Compartment for 4-6 Hours of Cooling] Equipped with a dedicated insulated pocket for the hydration pack. The thick foam insulation layer blocks heat transfer from your back, keeping cold water cool for 4-6 hours even in summer. You can drink cool water during long-distance cycling or mountain climbing in sweaty seasons.
[18L Large Capacity x Lightweight Design for Excellent Usability] Despite its lightweight design of only 512g, it boasts an 18L large capacity. In addition to the main compartment, it features multiple pockets, including a velvet-lined accessory pocket, a front pocket, and mesh side pockets. It efficiently stores everything from small items to clothing.
[Breathable x Adjustable Straps for Comfortable Carrying] The breathable shoulder straps feature a raised ventilation design on the back to wick away sweat and prevent stuffiness. The chest strap and waist belt are ergonomically designed to fit your body, making them comfortable to wear for long periods without fatigue.
[Safe Design for Rainy Days and Nighttime] Made of water-repellent nylon material, and comes with an attached rain cover for sudden downpours. Multiple reflective tapes are placed on the bag to increase visibility to vehicles during nighttime cycling or running, ensuring safety.