PP Double Shell Jar 33mm for PreRolls. Our 33 mm PP double shell was designed for easier access to your pre-rolls. The double shell provides a smooth interior so your pre-rolls do not get caught inside while also maximizing label space & deco area. We supply the Double Shell pre-assembled and can offer this package with a plug to close the bottom. Preserve volatile terpenes with foil lined 33 mm closures to seal both inner and outer jars.