Wing trees have an ÒXÓ design for lateral and horizontal strength. Available in 16" and 18" tall versions, each tree is adjustable and will extend up to 6" with adjustment holes located at 1" increments. 16" trees are ideal for X wedge cars to keep the back of the top wing lower while providing optimal top wing tilt at high speed tracks. 4130 chrome moly 3/4" x .060" tube construction. Wing trees are 26" wide at the top and have a min/max bottom width of 25-3/4" to 26-1/2". Adjuster pins not included.