This portable, pre-school training bar is made of heavy-duty tubular steel. The 53" rail is 1" in diameter, with a white birch laminate surface. The rail adjusts in 3" increments from 33" to 48". Full assembled, the unit covers 53" x 53" of space. The training bar is specifically weighted in the base for more stability and adjusts with a hand wheel and pop pin. Perfect with a 4' x 8' Senior Folding Mat.