The Roto Chip Bait Holder is deadly for salmon.  It is for 4 to 4.5 inch anchovies, herring or other baitfish.  The bottom two models in the photo show this item.  The top two items are the Big Fin baitholder which is for 6 to 7 inch bait.  These baitholders come with the Pro-Troll Electronic EChip which attracts salmon with tiny electric nerve pulses.  The diagonal fin on the back causes the bait to roll with an erratic action.  This lure comes with two tandem barbless size 5/0 stainless hooks.  When the wire clip is pulled back the baitholder springs open for loading your baitfish.  Push the clip forward to secure the head of the bait.