Verify System Compatibility – Check your vehicle owner's manual or the AC system service label to confirm it specifies R1234YF refrigerant. This product is intended only for systems labeled for R1234YF use HFO-R1234YF Refrigerant – Sourced through authorized distributors and includes a ZeroR service sticker for proper system labeling 8 oz Can Weight – Refrigerant is measured by weight, not by how it feels when shaken. The listed net weight is accurate. Different refrigerants have different densities, so weight may vary. Most R1234YF systems typically use 2–3 cans Reverse-Thread Design – R1234YF cans use reverse threads; compatible tools connect by turning counterclockwise