Look for the FCC ID - Make sure the replacement key fob has the same FCC ID as your original key fob.It is usually located on the back of the key fob or inside the battery compartment.Reference for P/N - FCC ID:KR5T21,Part number:72147-TJB-A01,72147-TJB-A11.The compatibility is just for reference,make and model car might have different keyless entry systems and key blade slots.Fits for Acura RDX 2019 - 2020.Check&Verify - Check the make, model,and year of your car.This information is usually listed on the owner's manual,registration or insurance documents,but it is just for reference,you also need to confirm the FCC ID,Part Number,Button Quantity&Function and Key Blade of your exiting working key is same with this remote control.Visit a locksmith - There is no manual way to program it by yourself.You would better consult a locksmith and have the remote key programmed and cut.Dealers are not recommended as they are only able to program genuine due to having limited software capabilities.Full Remote Key - Each of keyless entry remote comes complete with battery/chip/circuit board/uncut emergency key.Please notice that this product without logo/emblem/part number on the back.