LA GUíA DEFINITIVA PARA PERPETUAL MARBLE MACHINE KINETIC

"I bought this for my wife's birthday,she loves marbles and we look at the videos on U-Tube with the marble machines. This is a perfect miniature replica of these machines well suited for a table top and very high quality construction, highly recommend it." Marble Machine "Duality" - Handmadepoint of the rail. In that case, how is the ball “boost