The best defense against unknown refrigerant and the risks associated with unknown refrigerant is a refrigerant identifier. With the new Robinair 16009 DiscovR 134a refrigerant identifier you can:Protect your A/C service equipment. Know whether or not you have acceptable R134a refrigerant before servicing the vehicle with the DiscovR refrigerant identifier.Guard against costly recovery equipment repairs. Contaminated refrigerant can wreak havoc on any R134a recovery, recycle and recharge machine. The average repair cost is $300, and in many cases contaminated refrigerant will void the product's warranty. Shield your RRR machine from contaminated refrigerant by using the DiscovR refrigerant identifier before connecting to the vehicle.Uncover hard to find air contamination. DiscovR refrigerant identifier notifies you when the system contains excessive air.Fast and Accurate. 'Pass" and 'Fail" lights clearly show if refrigerant is pure enough to be recovered.