Build your own custom scaffold tower to fit your specific needs for home repair, maintenance and building construction. The 31 in. Adjustable Stem is designed for use with exterior scaffold units in conjunction with the 5 in. x 5 in. Plain Base (Base Plates not included) or the 8 in. Heavy-Duty Caster (both sold separately). The Adjustable Stem allows you to adjust the scaffold height to compensate for uneven terrain and maintain a level surface on the walk boards.