Yellow Jacket, a brand of Ritchie Engineering Co. Inc.: Refrigerant Hoses

Designed to service mini-splits, this product combines a Flex Flow hose with a ¼- to 5/16-inch coupler.

source https://www.achrnews.com/articles/141718-yellow-jacket-a-brand-of-ritchie-engineering-co-inc-refrigerant-hoses