Size 2 long shank Hook.
For a fly design that ended up being pretty simplistic, a lot of prototypes and testing went into the development of this pattern. Tied on a long shank hook, the rear end dips down into the water at an angle during retrieve. most of the body of the fly is under the surface and the hook point is fully exposed to a curious trout. The synthetic yarn that constructs the body gives a solid profile to a fish from below and sheds water better than rabbit does during the cast. The angular head and ears create an attractive wake as they prop the body up and keep it from spinning or diving on a fast retrieve. I utilize a small tab of special glowing foam hidden (from fish) between the ears that will glow for 30 minutes without being recharged. Being able to see your fly at night will make you fish much more effectively. A visible glow spot lets the angler understand river currents, place the fly close to structure and cast over obstructions. Maybe even more importantly, watching that glowing tab disappear and hearing an explosion that actually scares you as a monster brown inhales your Trap Mouse will be something you never forget!