The TSA dictates to travelers who wish to bring aboard liquid toiletries, that they have them in bottles no larger than three ounces. 

Second, they must have these plastic bottles in a one-quart size clear plastic bag. 

Third, air travelers must place this one zip-top bag in a bin when moving through the security X-ray checkpoint at domestic airports.

The Travelon 1-Quart Zip-Top Bag with TSA Approved Plastic Bottles allows you to abide by the carry-on regulations set by the authorities and offers you four quality bottles and two jars to carry the liquid toiletry essentials you need.  The clear PVC bag is clearly marked as a one-quart size bag and has a convenient zipper opening--"clearly" an improvement over a standard kitchen sandwich bag.