The 42 mm X 33 mm clear shrink bands are available here in a bulk option and are compatible with a handful of our products, mostly being 4 oz glass round and boston round bottles. These shrink bands give products a tamper-evident seal that ensures their safety and creates overall better quality packaging. These shrink bands are simple to remove with a single vertical perforation and can be paired with our heat gun kit to assure that they will be applied evenly and rapidly.