A89 - Jahn® Scaffold Jack is an all-steel unit designed to fit 24" x 24" and 16" x 24" tie and waler spacing. This jack is equipped with a built-in guard rail receptacle and is designed to hold two 2 x 10 planks for a comfortable work platform. The scaffold jack attaches to two "A" brackets with the horizontal rod and is equipped with nailing holes top and bottom to secure it in place. Maximum spacing for the A89 jack is 8'-0".