A storage container for all liquid black&white and color developers. Extends developer life by eliminating destructive air. Made of heavy wall polyethylene, Air-Evac is air proof and durable. As developer is used, compress Air-Evac until liquid is level with the top of the container opening and screw the cap on. Air-Evac will remain in this position, locking out air until you are ready to use again. When empty, Air-Evac can be expanded back to its full gallon size to be used over and over again. Plastic-coated, wipe-off label.