Imitation....er....attractor pattern? This stonefly is a great blend of attractor components and lifelike features. 

Big nymphs have two jobs: entice fish and get the entire rig to the bottom. The Flow Stone does both.

The King Tubby Stone is a great stonefly nymph that will fool fish looking for big bugs!

A stone that gets down fast.  Way down.  Real fast.

The nymph version of Matt Callies's Big Arse Soft Hackle.  This is a stonefly with all the bells and whistles.