In this video, Mecanica 6mm reviews the Neptune 10" Plus from Rossi, an airsoft gun with a 10-inch barrel and a programmable electronic board. He tests the gun’s range, accuracy, and performance before and after preparing it with 6mm Mechanics. He also shows the internals of the gun, including the connector, shimming, motor, gearbox, piston, cylinder, air nozzle, o-ring, gears, and hop up chamber.