40/400 Black Phenolic Royal Cap F217

For Part 135650, the central question is how the compression-molded closure behaves in the assembled package. The 40/400 designation should be verified dimensionally because nominal finish names do not guarantee identical sealing behavior. Appropriate markets can include prestige beauty, wellness, pharmaceutical, supplement, and specialty-product packaging. Qualification should cover thread engagement, liner compatibility, line application, and expected storage conditions. That discipline protects both package performance and the consumer experience.