In addition to Spro's, I have used the Fluke-Rat jig with success. They are different in that they are similar to a fluke ball, but have a different shaped head and a swinging hook, which imparts a bit of action.
Don't have a picture, but here is the website.
http://www.tidaltails.com/Fluke_Rats_Stingers.htm
Nice find 
You fishing them the same as a Spro?
Have you fished them in the deep yet?. I see they only go up to 4 ounces & there are times when I need 6
I use much shorter rod action because of the swinging tail. I fish with a guy who only uses these, and only moves his jig with very slight jigging motions keeping it on the bottom. Last summer he nailed a 10 lber with a 2 oz Fluke Rat tipped with a single spearing in the Reach channel. You can also replace the swinging bucktail with a leader of 4 to 6" add a sharp owner or gami hook tipped with a curly grub, spearing,squid, etc....so many ways to fish a bucktail.
In deeper water with fast current, I keep my conventional reel un-engaged and backslide to keep it on the bottom. Too much current, I go to a heavier spro or on rare occasions I use an 8 oz Mai Tai.
