Nonmetallic- undetectable to metal detectors or x-ray scanners. * Reusable- Washes clean with soap & warm water. * Screw top- Convenient leak proof screw top. * Durable- High quality food grade plastic is odor proof, leak proof, & puncture resistant. * Sturdy- Bottom gusset allows pouch to stand straight. Freezable- Freeze overnight for cool drinks all day.