Simplify laying curves or perfectly aligned straight tracks on 2-1/2" centers with this handy tool set and the CURVETRACKIT OR STRAIGHTRACKIT (both sold separately). The EXTRATRACKIT makes it easy to build larger or smaller radii curves using the CURVETRACKIT as a guide too. Lightly spike a standard curve in place, then place the EXTRATRACKIT above the curve for a larger radius, or below for a smaller. Remove the original curve to complete your project quickly and easily.