Thanks to its patented memory hinge, the Twixit Mega Bag Clip has been shown to open and close more than 1,000,000 times in independent tests - while in extreme temperatures. Twixit's unique bag clips are made of polypropylene plastic, which is approved for contact with food. The 9-1/2-Inch clip is big and sturdy enough to reseal large, thick and oversized bags such as dog food, kitty litter, charcoal, fertilizer, compost and flour bags. Use them to organize around the garage or shop too. Defective return guarantee from Twixit. Made in Sweden.