This pack contains 2 lane curved transitions, in various radius, and lengths at 15 degrees. The 50mm 75mm and 100mm Lengths refer to the length between the faces before angling them. so the 50mm will provide the shortest turns and the other 2 options will add 25mm and 50mm respectively to the length of the turn. The 100mm long 250mm Inner Radius will be the largest part and it's widest point is 228 mm. Where as the 50mm Long 115mm Inner radius is 143mm at it's widest point. This track turns Left