[header] How to copy a key fob [title] Purchase an rfid writer online. [step] An rfid writer is capable of reading and writing 125khz key fobs. Search online for an rfid writer and reader and purchase one that has good user reviews. 
[substeps] Some rfid handheld readers and writers will come with blank key fobs that you can use to make a copy. 125khz key fobs are commonly used to lock doors in office buildings and apartment complexes.