A quick and simple method for assembly of LARGE square and rectangular tubing. Unique design allows assembly of several hundred different sizes of square and retangular shapes. Use for concrete columns in the construction of modern structures. May also be used to represent square steel or wood members in the construction of older structures. Also good for making boxes or other creative craft items. 1/16" (1.6mm) alignment lip and notch corners allow fast, accurate assembly. Simply tape assembly together, then solvent bond along the joints. Precision injection moulded in light grey ABS plastic. Sold in single 760mm lengths. (Also available in clear acrylic plastic.)