Those are a knockoff of the Cubby NailTail. I use both, but prefer the NailTails. I use them on 1/32 and 1/16 oz standard, spurless, roundhead jigs. The jigs have no keeper spur like used with curly tails as these tails are too small in diameter to go over a spur without splitting. To find jigs without the spur you may have to order them from one of the crappie.com members that make jigs.