Troutline Tactical PD Nymph No10 is one of the best nymph for trout and grayling. This fly has all the elements needed for make the fish to strike it: hot spot, slim body to sink fast, CDC for movement and dark body colored to provide a good contrast in all type of waters. Silver bead imitated the air bubble used by emergers to lift up in the water column.
It is a great all around model which catch lots of fish in all fishing conditions.
The nymph comes in two different hook sizes: