This is an N scale set of two Alco C-855 drive shaft extenders to be used with later Con-Cor U50/Turbine chassis that have twenty tooth cup gears when converting them for C-855 use. They are designed to be used with a James' Train Parts Alco C-855 locomotive kits.
These parts are designed to be printed the FUD & FXD materials and they will require cleaning before painting. I recommend washing with warm soapy water then soaking in 'Goo Gone' or similar product for about 24 hours. Then rinsing off with warm water and allowing to dry.
For more information please see my blog - www.jamestrainparts.com