Our patented ZipDry® seal is what sets our bags apart. Snap it shut like a freezer bag, and anything inside is protected - even underwater. Opening - Do not force bag open by pulling the tabs apart! ZipDry bags have a very tight, completely leak-proof closure; improper opening could compromise the seal. - Grip bag by its closure with both hands, laying thumbs over the grip tabs. Keep index fingers on the tracks of the seal. - Squeeze and kink closure into both palms, forming and "S" with hands offset. Bag will pop open easily. This technique becomes easier with a little practice. Closing: - Make sure closure is clean and properly lubricated with silicone spray or similar lube. If in the field and none of these are available, use oil, saliva or water in the closure tracks as necessary. Cleaning and Lubrication: - This closure provides a very close-fitting rubber seal. It is therefore necessary to occasionally clean and condition it to maintain ease of use and reliability. Thoroughly clean tracks. - Spray lubricant/ protectant (we recommend 303 aerospace protectant) on to brush and thoroughly brush into full length of closure. - Snap closure together and pull apart a few times to evenly distribute lubricant/protectant. - It is recommended to store closure in closed position to prolong time between cleanings. - If lubricant/protectant is not available, similar products are effective. In the field, any lubricant, saliva, or water will work to help close the tracks if they are dry.