This set includes crossing rails that allow for the replacement of double-track rails, and 45-degree crossing rails that are half the length of straight rails. To accommodate adjustments when incorporating them into a layout, we've included 1/3 rails, 1/6 rails, and adjustable-length rails in the set. Set Contents: Double-track crossing rails x 2 45-degree crossing rails x 2 1/3 straight rails x 2 1/6 straight rails x 2 Adjustable-length rails (52mm-84mm) x 2 Male-male joint parts x 10 The crossing rails have female joints, so please use the included male-male joints as needed. The adjustable-length rails are designed to come apart if stretched too far. Simply reattach them for use. ※ This product is a personal creation made with a 3D printer. Please be aware that due to the manufacturing process, there may be stripe patterns, color variations, and surface imperfections. ※ The material used is PLA, a plant-based plastic. Please be careful as it is prone to deformation in high temperatures.