New Ziploc brand Storage Slider Bags are designed with new Power Shield technology that provides unbeatable protection for your food. New more durable film with an expandable bottom, Ziploc brand Storage Slider Bags outperform the competition in strength and reliability*. Each bag blocks out air and locks in freshness ensuring that your food stays fresh, meaning less wasted food and more money saved. *Bag film tested using AS D1709 Dart Drop and AS D2582 PPT.