Product description: consisting of four 18"(45 cm) long wooden blocks each with ten inset knobbed cylinders graded in height andor diameter. In block no.1 - the cylinder increases in both height and diameter. In block no.2 - cylinder increases in diameter but remain constant in height. In block no.3 - cylinder decreases in height but increases in diameter. In block no.4 - cylinder increases in height while diameter remains constant. Additional information: pay mode terms: lc (letter of

Product description: consisting of four 18"(45 cm) long wooden blocks each with ten inset knobbed cylinders graded in height andor diameter. In block no.1 - the cylinder increases in both height and diameter. In block no.2 - cylinder increases in diameter but remain constant in height. In block no.3 - cylinder decreases in height but increases in diameter. In block no.4 - cylinder increases in height while diameter remains constant. Additional information: pay mode terms: lc (letter of