"IF YOU CAN'T TELL THE DIFFERENCE, WHAT DIFFERENCE DOES IT MAKE!" If you want more elaborate posts for your fencing, gates or entrances, our 12" x 12" x 64" Rock Pillars(height includes 5" cap)or our 21" x 21" x 56 1/2" Stackable Ledgestone Pillars (height includes 10 1/2" cap)are a beautiful choice! You can stack the 21" x 21" as high as your internal structure will support. Each stack section is 15 1/2" high. For example, one pillar plus one stack section is required for a 6' tall fence. They are formed with heavy wall Medium Density Polyethylene (MDPE) and are impact resistant and very durable. Several different colors help make the difference!