If you just purchased your unit, the security code should be written on a wallet size card taped to the front or top of the unit. With some units, the code is hand written on the top of the unit (usually on the label) and it would be a 4 digit number.
If the code received with your unit does not work, please try the following default codes:
RHR - 1234
RHB/RBZ - 0000
Sometimes we receive radios that do not prompt for a code, due to the canbus we use on our bench testing equipment. if you received a unit with no code and cannot find it on the label please contact email@example.com or firstname.lastname@example.org to have the code sent.