Plastic seals Variable length seals, commonly called "pull tight seals" can fit many applications from securing the neck of a bag or mail sack to sealing chemical drums, first aid kits and fire extinguishers. They have an adjustable length much like a cable tie but offer a much higher security level and an audit trail due to sequential numbering and the ability on some seals to be bar-coded and have a company name and logo printed or laser etched on.
Until the 18 mm minimum diameter becomes effective, seals shall be designed and constructed
so as not to permit removal without breaking. Once the 18 mm minimum diameter has become effective, all
bolt seals shall meet this requirement in order to be ISO 17712 compliant.