Blow back rigs are an anti-ejection rig that are based on the carp (or other specimen fish) taking the baited rig into the mouth and then coming into their own by making it difficult for the fish to disengage from the rig.
Here are some useful articles on carp blow back rigs on external webpages:
The blow back rig by instructables.com
Tying a blow back rig by Dream Carp Holidays
Blowback rig components: BROWSE NOW
VIDEOS:
Watch videos about the carp fishing blow back rig.