You can choose from two different birch arches that we have. Both have the ability to be 4-post or 2-post. 4-post is excellent for chuppahs and mandaps. One arch is larger than the other and the other difference is the smaller of the two arches has three tree poles that make up each corner pole. The larger arch has thicker singular poles for each corner. These arches are beautiful for outdoor weddings and can be staked into the ground so that there is no issue with strong wind knocking them over.