【Innovative Vacuum Compression Backpack & Battery-Powered Electric Pump】The backpack is equipped with a vacuum compression bag inside. Open the exhaust valve and use the electric pump to complete compression in 10 seconds, reducing the volume by 60% quickly, allowing you to neatly store bulky clothing during travel or business trips. Notes: ① To ensure the airtightness of the vacuum compression bag, a TPU rubber layer has been added to the zipper, making it difficult to open and close when used for the first time. However, it will gradually become smoother with repeated use. ② Batteries are not included with the electric pump. Please prepare 6 AA batteries in advance. 【Expansion Function & Compression Function & Excellent Storage Capacity】Business backpack size: (Before expansion: 25L - daily commute) 50*34*15cm → (After expansion: 30L - short business trip) 50*34*20cm → (After vacuum compression: 50L - 1-5 night trip) 50*34*23cm. With a smart capacity change from 30L to 50L, it can be used in any situation, from daily commuting and school to outdoor activities, overseas travel, and business trips.