3D printed track cover for Sankyo machines with acid green back plastics, can fit over versions. White version in the picture is the 3D printed product, it is about 5.75 " long. (Check with us on other versions to verify fit) The 3D printed design uses a friction fit on the slider instead of the spring seen on the original, if you want to install a spring you can but it is not necessary. If you are not sure if this is the right one to use, send us a picture of the back of the machine and the track area and we can match it up. Includes instructions along with the part, and shipping is included.