Open track, easy to start, just dial by hand, intuitive visual sense, easy to understand the demonstration. The back acrylic plate is the base plate, the support position is connected with the card buckle, the overall structure is sturdy and durable. The coil is made of high temperature enameled wire, low power, low heat, no rust. Adopting stainless steel wire to make the ring track, fast reaction speed and smooth running. Precision circuit board, each coil a separate circuit board, do not affect each other.