The heat-shrink bands found on NALGENE® Sterile PETG Square Media Bottles are now available separately. These bands provide a tamper-resistant seal to ensure the integrity of the bottle contents. Simply apply the recommended application torque for NALGENE closures, and slide the heat-shrink band over the closure and bottle neck; heat the band to shrink and secure contents. Bands are gamma stable and include a perforated “tear strip” feature for easy removal. They are available in 4 sizes to mate with NALGENE PETG Square Media Bottles.