I don't understand when I bought it but that is for the new R-1234yf refrigerant which uses reverse thread cans to mix with R Avoid -134a. This will not work with R-134a cartridges as they are left-hand threads. For R-134a, search "Self-Sealing Tap R134A Right Hand Thread". However if you need a new R-1234yf this is a very well built valve and I recommend it.
VIVOHOME 220LB HVAC Electronic Digital Refrigerant Charging Weight Scale β High Precision with Protective Case
9 Review
Robust Robinair (RG3) Portable Refrigerant Recovery Machine, 115V, 60Hz -Efficiently Recovers Liquid and Vapor Refrigerant
9 Review
Enhanced Elitech ILD-300 Infrared Refrigerant Leak Detector: Advanced HVAC Halogen Tester with Selectable Gas Functionality
9 Review
π¨ Robinair (15115) VacuMaster Single Stage Vacuum Pump - For Efficient Single-Stage Vacuuming, Delivers 1.5 CFM
9 Review