Maximum height (level to level): 80mm Set of seven piers in different heights clip to the underside of Hornby track to create a smooth incline, straight or curved. Piers have grooves to accept R660 elevated track sidewalls. The minimum track running length to a height of 80mm with supports at 24 sleeper intervals is approximately 1344mm. However for a more gradual incline with the supports at 30 sleeper intervals the overall running length increases to approximately 1680mm.