These are tough, waterproof, non-tear, non-stretch drinking age patterned wristbands available in a variety of colors and featuring an invisible ink allowing the pattern to come shining through under UV light. All wristbands are consecutively numbered. They come with a very strong adhesive and have tamperproof slits making them impossible to remove in one piece for transferring to another person. These Tyvek wristbands are 10" long and 3/4" wide.