R-421A Refrigerant Decal Stickers - 10 Pack EPA regulations require that whenever a refrigerant retrofit is performed (recharging or converting a refrigeration / AC / Heat Pump system to use a substitute refrigerant, usually from HCFC R22 / R-22 to an HFC blend), the system must be properly marked. This R-421A conversion decal is to be affixed to the exterior of the system in the most visible locations so that any technician would easily see them. Multiple stickers are recommended in locations such as the primary servicing panel, the electrical disconnect, near the refrigerant access connections, inside the electrical panel, etc. On split systems place one at the air handler location as well. When used in combination with a Refrigerant Retrofit Report this leaves a readily identifiable record for the next technician so they will know what alterations have been made and what they are working on. These decals are for professionals who want to do the job right instead of writing on the side of the unit with a marker that nobody will even be able to read one year later! For a bulk purchase / large quantity wholesale discount please message us. Decal design and imagery Copyright 2022 RefrigerantStickers.com / SSP LLC and may not be copied, reproduced or used in any way without our express written consent.