The Birthplace of Abraham Lincoln National Park uses copper pyramid post caps to protect their walkways and ramps. When this national park was looking for the best, most durable copper fence post caps on the market they chose post caps from Post Cap Depot. These post tops measure 4x4 and they are made from the thickest copper on the market. They do not have a coating so they will patina to a green color which is exactly what Abe wanted! As a result they now enjoy a lifelong product to protect their bridges and fences.