Wtf , now that ' s something you should really make a consumer complaint about the base was clearly shown in all promo pictures . But I guess the rest is also crappy like this , eh ? <| sep |> There ' s an article about this in the MayJune Scientific American called Can Infection Give You the Blues ? by Erich Kastenedit link af infectiongiveyoutheblues <| sep |> I realize this post is old , but here ' s some additional information that I hope you ' ll find useful . These 125 kHz fobs are extremely easy to copy . The Chinese copiers I ' ve used work well and should cost you about $ 825 . They are handheld , run on batteries , and do not require a computer . Just make sure it ' s supposed to copy 125 kHz tags . Fobs should cost no more $ 1 each if you ' re buying at least 10 . Get ones with T 5577 chips . I believe the chip in the fob photo you posted is EM 4100 , but those are readonly . T 5577 tags are rewritable and come in a variety of form factors . You ' ll frequently see them as cards , fobs , bracelets , and stickers like a generic looking coin with sticky tape on it on various China import websites . I have a Proxmark 3 , and can read , emulate , or clone many low frequency RFID tags . It ' s pricey , but nice for investigation if I run across an unknown tag . A few tips . Don ' t buy EM 4100 tags , as those are preprogrammed . And while you can use EM 4305 tags for access control , they aren ' t compatible with HID . If you see a listing for a USB reader that says HID that isn ' t HID branded , those are often Human Interface Device readers that emulate a keyboard to type the card ID and press enter not useful in most cases .