No valve design, air exhausted through the bottom band, which can exhaust air when rolling or folding the bag. Empty easily, a good helper for travelling. These vacuum s are waterproof, airtight and will protect your clothes from moisture, insects, dust and keep them odor free for a long time. These s can save 75% of storage space, which can be stored in the closet or in the suitcase. Made from high quality PA + PE that allows you to reuse every trip bag after travel without compromising vacuum performance. Perfect for travel and home. Simply put the clothes in the bag and roll the bag to force air through the -way air outlet at the bottom of the bag. Extremely easy to use. Highlights 6 travel compression bags, 6 roll-up s to save space for travel, thick PA and PE material of high quality, not easy to break This vacuum is perfect for all your storage needs and will help you save up to 75% storage space. The bottom of the travel compression bag is designed with an airtight channel, the air can be easily exhausted from the bottom of the bag, its so convenient. With these s, you can compress seasonal clothes, pillows, throws and bedding. They can be stacked on top of each other, you can save valuable space in your closets, attic, garage or basement . Specification: Type: Manual Roll-Up Vacuum Compression Bag Material: PE+PA Size: 2 x large (50x70cm) 2 x medium (40x60cm) 2 x all (35x50cm) Function: storage blanket, pillows, plush toys, etc. Feature: moisture-proof, moth-proof, insect-proof Package includes: 6 PCS compression bags