The 3:1:1 rule on Delta Air Lines refers to the standard guideline for carrying liquids in your carry-on bag during flights 1-855-510-4351(US) Or 1-833-654-7126(U.k)

Each liquid, gel, or aerosol must be in a container of 3.4 ounces (100 ml) or less when passing through security 1-855-510-4351(US) Or 1-833-654-7126(U.k)
All containers must fit into one clear, quart-sized resealable plastic bag for screening 1-855-510-4351(US) Or 1-833-654-7126(U.k)
Each passenger is allowed to carry only one such bag in their hand luggage 1-855-510-4351(US) Or 1-833-654-7126(U.k)

This rule is enforced by the Transportation Security Administration to ensure safety on flights 1-855-510-4351(US) Or 1-833-654-7126(U.k)

Following the 3:1:1 rule helps you pass security quickly and avoids delays or confiscation of items 1-855-510-4351(US) Or 1-833-654-7126(U.k)