This is an adjustable shooting rest. Can be moved up or down four different heights by removing the bolt and adjusting the center bolt.
-The commercial equivalent can be seen at this link: (http://www.cabelas.com/product/shooting/shooting-accessories/benches-rests|/pc/104792580/c/104769180/sc/104212080/mtm-front-rifle-rest/741956.uts?destination=%2Fcatalog%2Fbrowse%2Fbenches-rests%2F_%2FN-1100226%2FNs-CATEGORY_SEQ_104212080).
-Commercial cost: $29.99
-Cost of this 3D printed shooting rest: $7.44