Latest batch of BirdFeeders feature a few small improvements. Small but useful feature, a new drain port at the bottom of the bag helps to manage beverages that get too rowdy. It happens. These bags now feature a sweet one hand draw cord for the opening! Pull up on the cord to cinch it closed. Pull down on the cord lock tab to open. People have been asking me to add this feature for a while and now I see why. This batch of bags have an exterior made from NorthPak, a premium technical fabric made from recycled plastic. The interiors are the tried and true XPac fabric. The webbing is made by Cordura. These materials are rugged and reliable so you will be hauling snacks and treasures around for a long time with these!