Your PEXA USB (or "dongle" as I like to call it!) actually has a SIM inside - just like a mobile phone. The SIM has the name of the certificate holder printed on it - useful if you sit your certificate on the table next to a colleagues and confuse them. This also means, there is a potential for the SIM to become loose in transit. This is something to try when troubleshooting the dongle (look for the tiny white dot that moves on the outside of the certificate to eject the SIM and re-seat). Of course, as always, feel free to contact the PEXA Support Desk 1300 084 515 or your Account Manager/PEXA Direct Specialist for assistance.