The present invention provides an assembly for extending the bed of a pickup truck, having a hitch receiver and a down folded tailgate past the end of tailgate and providing a ramp function. A pressurized propellant gas for atomizing an unatomized fluid can be introduced into the atomizing tube. Carbon dioxide is then introduced to the isolated atmosphere in a series of three, four, five or more phases to humanely stun and eventually kill the poultry. An optical fiber with a lens is disposed in each of the V-shaped grooves. The guide member 14 has a through hole 15 for passing the operating shaft 11.