The Grom Fire Bird model is the kids version of an all-round everyday shortboard. with a curvier outline, lower rocker plus more forward thickness under the chest and front foot area.
This  allows for easy paddling, fast down the line speed, combined with a single to double concave bottom and pulled in rounded square tail for pivot and release. 

Stock Dimensions            Volume    
5'2 x 17 3/4 x 2                19.01L
5'4 x 17 7/8 x 2 1/6          20.18L
5'6 x 18 x 2 1/16              21.33L
5'8 x 18 1/2 x 2 1/8          24.21L