Horiizontal Economy Urn Vault This topseal unit is made of lightweight high-impact polystyrene. It weighs 8 pounds. The outside measures:10.5"Hx16.5"Wx19.5L. The narrow inside measures: 10.5"Hx8.5"Wx11"L. The wide Inside measures: 8.75"Hx12"Wx15"L. When choosing a vault the inside measurments are the most important so that your urn fits inside and the top can go on and be sealed. The outside of the urn must fit into the inside of the vault. Contact Lovedonesurns for assistance when placing an order for any vault and we will assist you so that you get the correct size vault. This vault could be used for a child or infant urn if you had some keepsakes in it. The goal here is not to confuse you, but to give you economical options.