This fly imitates a stage in the life cycle of a mayfly where it is most vulnerable to trout predation: the trip from river bottom to the surface to hatch. When a mayfly nymph is close to emerging, its skin falls up with gas, it becomes buoyant and it floats to the surface. Some mayfly nymphs resist this upward float and try to swim back down to the shelter of the rocks, resulting in a series of up and down motions: the motion the Leisering Lift is intended to imitate. This fly imitates this stage of the nymph as the clear beads reproduce the gas filled skin and reflect light on the nymph's trip to the surface. Fishing this fly with a series of lifts to imitate the nymph that refuse to hatch and till it's exhausted with swimming back down.