It's a Tricky Senko! If the standard 5-inch 9-series Senko is dynamite, then the slender 5-inch 9M Senko is a loud firecracker. The 9M is custom made to compete and win in any trick worm or slender worm situation. What the 9M has that the others don't is it always produces that unique Senko characteristic of shimmying and shifting with tip quivering action. 10 per bag. Model 9M-10.