Relay clips where the beginning of the modern cascade rigs as now used in most trace designs an original idea by Nigel Forrest, These are still used in large numbers by rig makers as intermeiate bait clips and as a cascade clips with an Impact shield or Lead as the master release. When used as a cascade type clip its better to cut off the spigot which is used with rubber to grip the trace line and fix with crimps or sliding knots, alsop used in up and over rigs.