24" H Carpeted Bunk Board Guide On Kit (86123) by Tie Down Engineering®. The 2x4 black carpeted bunk boards are offered in 24" lengths. Posts can be mounted 5-11" on the side of the frame. If mounted above the frame, bunk placement is 19" high. U-bolts and nuts are zinc plated, and mounting hardware is galvanized for corrosion protection. Kit fits frames 2-3" wide and up to 4" high.