Pack contains two 144mm long platform units that simply clip to the ST-91 Stone Type Complete Platform system to make a longer platform.As supplied the units fit a standard track configuration but it is easy to adapt to suit other situations; just cut the platform surfaces to any of three widths by following the scribed lines on the back. Ramps can be made to one of two widths, and have curved sides to match the Setrack curve. See our Useful Guides Section for publications that will give you tips, instruction and inspiration on building a great model railway.