These premium black jars offer a sleek and compliant glass packaging option for businesses needing compliant opaque packaging. These 4 ounce black injection glass jars are light resistant to keep products fresh. The caps feature a flush push down and turn cap with a seamless smooth flat top for all labeling and branding applications. All caps come with an insert liner to keep the jar air tight to achieve the perfect seal when caps are closed. The 4 ounce glass jar is the most popular 1/4oz flower jar with , pre-packagers, and delivery services.