Here is an example using the sysobject id to get the model of the box.
event manager applet model
event none
action 010 cli command "enable"
action 020 cli command "show snmp sysobjectid"
action 030 regexp "1\.3\.6\.1\.4\.1\.9\.1\.([0-9]+)" "$_cli_result" match modelid
action 040 syslog msg "sysobject = $modelid"
action 050 if $modelid eq "1496"
action 060 syslog msg "sysobject index $modelid is an 819 router"
action 070 else
action 080 syslog msg "sysobject index $modelid is not an 819 router"
action 090 end